<PAGE>

                                                                    EXHIBIT 10.5

                       SEPARATION AGREEMENT AND RELEASE
                       --------------------------------

     This Separation Agreement and Mutual General Release ("Agreement") is made
and entered into and the 2nd day of May, 2001 (the "Effective Date," which is
defined as the date the Parties sign this Agreement), between Mannatech, Inc.
and its affiliates (defined as any entity which owns or controls, is owned or
controlled by, or is under common ownership or control with Mannatech)
(collectively as "Mannatech"), and Deanne Varner ("Varner"). Varner and
Mannatech are collectively referred to herein as the "Parties."

     WHEREAS the Parties desire to finally, fully and completely resolve all
disputes that now or may exist between them concerning Varner's hiring,
employment and termination from Mannatech, and all disputes over benefits and
compensation connected with such employment, and specifically, but not limited
to, any disputes arising from the terms of Varner's employment as set forth in
the Employment Agreements entered into between the Parties dated May 14, 1997
and September 28, 1998 ("Employment Agreements").

     NOW, THEREFORE, in consideration of the premises and mutual covenants and
agreements hereinafter set forth, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the Parties hereto
agree as follows:

     1.   Varner hereby submits her resignation from employment with Mannatech
as General Counsel, Senior Vice-President and any other job or position held,
and acknowledges that her employment with Mannatech ends the 8th day after the
Effective

                                     Page 1
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Date of this Agreement, which shall be designated as the "Separation Date."
Varner also hereby resigns effective immediately from all positions (including
any positions as Officer or Director) with any Mannatech subsidiary or affiliate
companies. Except as expressly set forth in this Agreement, all benefits and
perquisites related to Varner's employment with Mannatech shall cease as of the
Separation Date. Varner agrees that from the Effective Date of this Agreement to
her Separation Date, she will be on administrative leave and shall not perform
any services or duties on behalf of Mannatech unless specifically directed to do
so by the President, Chief Executive Officer or Chairman of the Board. During
Varner's administrative leave, she shall receive her normal benefits and salary,
in accordance with Mannatech's regular salary payment schedule. Except as
otherwise required pursuant to this Agreement, no further salary, bonus,
benefits, payments, warrants, stock or options shall be due from or paid by
Mannatech to Varner, and Varner hereby waives and relinquishes all claims to
further employment, compensation, benefits, stock, warrants, options, or other
remuneration from Mannatech, except as specified in this Agreement. Varner
agrees that any remaining warrants or options which have not previously vested,
are forfeited. Varner agrees that this release is binding on her, her heirs,
legal representatives and assigns.

     2.   Any vested interest held by Varner in Mannatech's 401(k) Plans shall
be distributed in accordance with the terms of the plan (the "Plan") and
applicable law. Varner shall not be a participant in the Plan after the
Separation Date, and shall not be entitled to any further contribution for any
period of time after the Separation Date.

                                     Page 2
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Mannatech shall provide Varner under separate cover at her address for notice
("Address"), information necessary and as required by law to facilitate the
transfer or rollover of her 401(k) account.

     3.   Except as provided in paragraph 7 of this Agreement, within five (5)
days after the Effective Date, Varner shall return all equipment and property in
her possession which belongs to Mannatech, including all files and programs
stored electronically or otherwise, that relate or refer to Mannatech, and
within fifteen (15) days after the Effective Date, she shall also return all
original and copies of documents, notes, memoranda or any other written
materials that relate or refer to Mannatech, including any material that
constitutes "Confidential Information" as such term is currently defined in Rule
1.05 of the Texas Disciplinary Rules of Professional Conduct governing the
attorney-client relationship. In addition, Varner agrees to permit Mannatech to
electronically examine all computer equipment that she may have used in the
course of performing her job duties. Varner agrees and reaffirms her duties to
Mannatech pursuant to the Texas Disciplinary Rules of Professional Conduct
governing the attorney-client relationship, and Varner shall not disclose
"Confidential Information" pertaining to Mannatech except as permitted by the
Texas Disciplinary Rules of Professional Conduct. Varner shall also not
represent any existing or prior Associate of Mannatech, nor shall she represent
any future Associate of Mannatech with regard to any matter concerning Mannatech
irrespective of whether adverse to Mannatech. Varner shall not represent any
other person or entity in any matter adverse to Mannatech.

                                     Page 3
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     4.   In consideration for the release and covenants by Varner set forth in
this Agreement, Mannatech agrees to pay to Varner a total of $900,000 payable as
follows: (i) the first installment will be paid by Mannatech to Varner in the
amount of $400,000 on the Separation Date; (ii) the second installment will be
paid by Mannatech to Varner in the amount of $250,000 on April 30, 2002; and
(iii) the third and final installment will be paid by Mannatech to Varner
of $250,000 on April 30, 2003. Each such installment to be paid to Varner will
be made in good funds via wire transfer to the account specified by Varner,
hand-delivery, or certified U.S. mail at her address as instructed by Varner.
(If Varner hereafter elects to change the instructions set forth, she shall
provide written notice to Mannatech specifying the new instructions for delivery
of the funds at least fourteen (14) days in advance of the installment due
date). Until such further notice is given by Varner, the funds shall be
transferred to Bank One, Texas, N.A., No. 14255, 1000 S. Beltline Road, Coppell,
Texas, ABA Routing Number: 111000614, for further credit to account of Deanne
Varner, Account Number 1560292896 (with Bank One, Texas, N.A. being requested to
call customer at 214-521-3778 upon receipt of funds.) Varner shall have no duty
to find new employment following the Separation Date. Any salary or remuneration
received by Varner from a third party for the providing of personal services
(whether by employment or as an independent contractor) following the Separation
Date shall not reduce the obligations of Mannatech to make any payment(s) to
Varner pursuant to the terms of this Agreement, including pursuant to this
Paragraph 4. Varner hereby agrees that she is solely responsible for all tax
obligations, if any, including, but not limited to, all

                                     Page 4
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reporting and payment obligations, which may arise as a consequence of such
payments. Varner hereby agrees to hold Mannatech and the Mannatech Re1easees
(described in paragraph 13 of this Agreement) harmless from and against, and
agrees to reimburse and indemnify Mannatech and the Releasees for any taxes,
penalties, net loss, cost, damage or expense, including, without limitation,
attorneys fees, incurred by Mannatech or the Releasees arising out of the tax
treatment by Varner on her tax return(s) of any payments made to Varner pursuant
to this Agreement, and/or arising out of Mannatech's payment of such lump sums
to Varner.

     5.   Varner and her dependent shall have the right to choose at Mannatech's
cost, extension of applicable medical insurance coverage pursuant to COBRA for a
period of up to eighteen (18) months. Mannatech shall provide, under separate
cover to Varner at her home address, information regarding COBRA election, and
Mannatech agrees to reimburse Varner for any premiums paid by her for
continuation of health coverage for Varner and her dependent under Mannatech's
group health plan, if any, pursuant to its COBRA continuation of coverage
provisions, for a period not to exceed 18 months, the period during which each
such individual is covered under COBRA continuation of coverage provisions. The
right of Varner to receive reimbursement of COBRA coverage shall cease if Varner
obtains full-time employment (which she is not required to do), and becomes
eligible for equivalent health insurance from her new employer. Varner agrees to
immediately notify Mannatech when she obtains full-time employment and becomes
eligible for equivalent health insurance.

                                     Page 5
<PAGE>

     6.   As further consideration to Varner, Mannatech will provide Varner
Options pursuant to the 2000 Stock Option Plan to acquire unrestricted common
stock of Mannatech, for the respective number of shares and respective exercise
prices as follows:

          Exercise Price       Number of Shares
          --------------       ----------------

              $1.75                 42,500
              $2.00                 37,500
              $2.25                 33,333
              $4.00                 50,000

The provisions of this paragraph shall supercede the requirements of the
Employee Agreements regarding the conversion of stock options to warrants,
including those requirements of Paragraph 8.1(16) (iii) of the September 28,
1998, Employment Agreement. Except as set forth in this Agreement, including
this paragraph 6, all unexercised stock options and warrants previously granted
to Varner respecting stock in Mannatech and Internet Health Group, Inc., shall
terminate on the Separation Date, and shall be null and void and of no further
effect.

     7.   Mannatech agrees, on or before June 30, 2001, to transfer to Varner,
free and clear title to the ownership of the Mercedes 430E owned or leased by
Mannatech and currently used exclusively by Varner ("Title Transfer Date"). From
the Effective Date of this Agreement to the Title Transfer Date, Mannatech will
keep the lease payments current, pay for maintenance and repair, and keep the
vehicle insured for its full replacement cost. In the event the vehicle is
damaged between the Effective Date and Title Transfer Date, and the cost of
repairs would exceed the depreciated

                                     Page 6
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value of the vehicle, Mannatech shall provide Varner with a replacement vehicle
equal to the depreciated value of her current vehicle. Once title is
transferred, Varner shall have sole responsibility for ownership of said
vehicle, including responsibility to secure insurance, licenses, taxes and
maintenance. Effective as of the Separation Date, and subject to the provisions
of paragraph 3 of this Agreement, Mannatech, without further action, shall also
be deemed to have transferred to Varner, title to the Gateway Computer and
monitor, and title to the Hewlett Packard PC, both currently owned by Mannatech
and used by Varner.

     8.   On the Separation Date, Mannatech agrees to pay Varner an additional
lump sum amount equal to one hundred and twenty-eight (128) hours of her base
pay ($24,236.64), less required state and federal deductions. In addition,
on the Separation date, Mannatech shall make a lump sum payment to Varner of
$24,062.22, less required state and federal deductions, which is equal to the
amount of accrued, unused vacation benefit time available to Varner from January
1, 2001 to April 20, 2001.

     9.   In the event of Varner's death this Agreement shall operate in favor
of her estate ("Estate") and all payments, obligations and consideration as
contemplated hereby shall continue to be performed in favor of her Estate.

     10.  The Parties shall issue a press release regarding Varner's resignation
from Mannatech as General Counsel and Senior Vice President in the form set
forth on Attachment "A" hereto ("Press Release"). Such Press Release shall not
be issued prior to the Separation Date, and shall be the sole public
communication by Officers and Directors of Mannatech regarding the severance of
Varner.

                                     Page 7
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     11.  After the Separation Date and through the last Installment Date of
April 1, 2003 ("Installment Payment Period"), Varner shall be available upon
reasonable notice to assist Mannatech at the request of the Company's Chief
Financial Officer or higher-ranked Officer, in such matters, including, but not
limited to, testifying (and preparing to testify) as a witness in any proceeding
or otherwise providing information or reasonable assistance to Mannatech in
connection with any claim or suit. Varner agrees to cooperate with Mannatech
regarding any pending or subsequently-filed litigation, claims or other disputed
items involving Mannatech that relate to matters within the knowledge or
responsibility of Varner during her employment. Varner agrees (i) to meet with
Mannatech's representatives, its counsel or other designees at mutually
convenient times and places with respect to any items within the scope of this
provision; (ii) to provide truthful testimony regarding same to any court,
agency or other adjudicatory body; and (iii) to provide Mannatech with notice of
contact by any adverse party (known to Varner to be adverse to Mannatech or its
interests), and further agrees that she will not voluntarily assist any such
adverse party or such adverse party's representatives. Varner shall be entitled
to reimbursement from Mannatech for reasonable travel and lodging expenses, if
necessary, incurred by Varner by reason of the requests of Mannatech made
pursuant to this paragraph. Varner shall be available to attend, on or before
August 1, 2001, two (2) days of orientation meetings with the new General
Counsel of Mannatech, provided a replacement has been hired by that date. In the
event a new General Counsel is not hired until after August 1, 2001, or in the
event the above-referenced

                                     Page 8
<PAGE>

orientation meetings are not held before August 1, 2001, then Varner shall only
be required to be available to attend a full-day orientation meeting with the
new General Counsel. The Parties agree that Varner shall be available to
consult, provide information or assistance, or otherwise cooperate with
Mannatech as specified in this paragraph, two (2) hours per month (at no charge)
during the Installment Payment Period, as follows: two (2) hours per month
shall, if unused, carry over from month to month, up to a maximum of six (6)
hours in any month (at no charge to Mannatech) during the Installment Payment
Period ("Allotted Time"). The Allotted Time available in any month during the
Installment Payment Period may be used within that month or accrued as stated
and limited above. In the event Varner is requested to perform services on
behalf of Mannatech in excess of the Allotted Time in any month, she shall be
compensated by Mannatech at the rate of $150 per hour in excess of six (6) hours
in that particular month. Varner shall keep an accurate record of her time
expended in performing services for Mannatech and shall submit monthly time
records (and statements for services, if applicable) to the Chief Financial
Officer of Mannatech. The Parties acknowledge that after the Separation Date,
Varner may undertake other business activities which are not precluded by this
Agreement which may require devotion of her full time. Therefore, the Parties
agree that any request of Varner's time by Mannatech pursuant to this paragraph
shall take into consideration Varner's other previously-scheduled commitments or
employment (which may be full time), and both Parties shall attempt to
accommodate the scheduling needs and requirements of the other (which may be at
times and on days which are not ordinary business times

                                     Page 9
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for Mannatech) in connection with the provisions of this paragraph. Further, the
Parties agree that consultations with Varner shall be by telephone whenever
possible. Mannatech recognizes that such post-separation date services shall not
be deemed to constitute legal services or the practice of law by Varner, unless
otherwise agreed in writing by Varner, but instead shall be deemed to constitute
business consulting services.

     12.  Varner does not release any rights to indemnity as provided under the
Bylaws of Mannatech or as set forth in Paragraph 2.6 of the September 28, 1998
Employment Agreement, that Varner may have possessed in her capacity, and by
reason of her service as an employee or officer of Mannatech. Mannatech shall
continue to maintain Directors and Officers insurance coverage, and will not
seek any exclusion for past Directors and Officers, including Varner. At the
written request of Varner, Mannatech shall deliver a copy of its Directors and
Officers Insurance Policy to Varner.

     13.  In consideration of the premises, covenants and other valuable
consideration provided by Mannatech in this Agreement, and subject thereto,
Varner:

          a.   Hereby releases Mannatech and its employees, officers, agents,
directors, shareholders and affiliates, collectively referred to as "Releases,"
from any and all claims, causes of action, losses, obligations, liabilities,
damages, judgments, costs, expenses (including attorneys fees) of any kind
whatsoever, including, but not limited to, disputes or claims arising out of
Varner's hiring, employment or termination of such employment with Mannatech,
including, but not limited to, disputes arising

                                    Page 10
<PAGE>

under the May 14, 1997, Employment Agreement, or the September 28, 1998,
Employment Agreement, between the Parties, or arising out of any act committed
or omitted during or after the existence of such employment relationship,
including any disputes regarding compensation, bonus, stock, warrants or
options. This Release includes, but is not limited to, all claims, whether
arising in contract or allegations of tort, common law or assertion of federal
or state statutory rights, including, but not limited to, Title VII of the Civil
Rights Act of 1964, as amended, or the Age Discrimination in Employment Act,
encompassing claims of age discrimination, claims for wrongful discharge, breach
of express or implied contract or implied covenant of good faith and fair
dealing, as well as any expenses, costs or attorneys fees. Furthermore, Varner
agrees and hereby relinquishes any right to re-employment with Mannatech.
However, Varner does not release her right to enforce the terms of this
Agreement.

          b.   Agrees not to engage or participate, directly or indirectly,
either as an employee, employer, consultant, agent, principal, partner,
stockholder, officer, direct, shareholder, member, investor (except passive
investments to the extent of 1/2% or less in a publicly-traded Company) or any
other individual or representative capacity during the Installment Payment
Period referenced in paragraph 4 of this Agreement, and for a period of one (1)
year following the last such installment payment (April 2, 2003) to Varner by
Mannatech, in any geographical area or market where Mannatech has conducted any
business as of Varner's Separation Date or during the previous twelve (12)
months:

                                    Page 11
<PAGE>

          i.   in any business competitive with the business conducted by
               Mannatech;

          ii.  render advice or services to, or otherwise assist, any other
               person, association or entity who is engaged, directly or
               indirectly, in any business competitive with the business
               conducted by Mannatech with respect to such competitive business;
               [however, subject to this Agreement, Varner shall have the right
               to engage in the practice of law]; or

          iii. induce any employee of Mannatech or any of its affiliates to
               terminate his or her employment with Mannatech or such
               affiliates, or hire or assist in the hiring of any such employee
               by any person, association or entity not affiliated with
               Mannatech [Varner's potential hiring of Vincenza Calvey within
               the first twelve (12) months after the Separation Date is
               specifically exempted from this provision].

          c.   Agrees to return to Mannatech all information described in
paragraph 3 of this Agreement and all copies thereof.

          d.   Agrees that she will not, save and except as required by law or
judicial process, at any time, make any disclosure of business information
maintained in confidence by Mannatech, or of any trade secrets of Mannatech, or
otherwise knowingly make any use thereof. As a result of Varner's employment by
Mannatech, Varner may also from time to time have had access to, or knowledge
of, confidential business information or trade secrets of third parties, such as
customers, suppliers, partners, joint venturers, and the like, of Mannatech and
Varner shall have the same obligation with regard thereto.

     The Parties agree that Mannatech has a legitimate interest in protecting
the business and good will of Mannatech that has developed in the areas of
Mannatech's business and in the geographical areas of this covenant not-to-
compete as a result of

                                    Page 12
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the operations of Mannatech. The Parties agree that Mannatech is entitled to
protection of its interests in these areas. The Parties further agree that the
limitations as to time, geographical area and scope of activity to be restrained
do not impose a greater restraint upon Varner than is necessary to protect the
goodwill or other business interest of Mannatech. The Parties further agree that
in the event of a violation of the provisions of paragraphs 3 or 13(b) (i-iii),
(c) or (d) of this Agreement by Varner, that Mannatech shall be entitled to
recover damages and all consideration provided to Varner in this Agreement,
terminate any and all payment then owing to Varner, and seek an injunction
against Varner for the breach or violation or continued breach or violation of
this covenant. Such remedies shall not be deemed the exclusive remedies for a
breach of these paragraphs, but shall be in addition to all remedies available
at law or in equity to Mannatech. The Parties agree that if a court of competent
jurisdiction determines that the length of time or any other restriction or
portion thereof set forth in this paragraph is overly restrictive and
unenforceable, the court may reduce or so modify such restriction to those which
it deems reasonable, appropriate and enforceable under the circumstances.

     14.  In the event Mannatech believes that Varner has breached any material
term or provision of this Agreement (with the exception of Varner's
Confidentiality, Non-Competition and/or Non-Solicitation covenants in paragraphs
3 and 13(b) (i-iii), (c) and (d)), Mannatech shall provide written notice to
Varner identifying the provision that Mannatech asserts has been breached by
Varner and demanding cure and performance of such term or provision by Varner.
Varner shall have fifteen (15)

                                    Page 13
<PAGE>

calendar days after receipt of such notice to cure such breach and/or to perform
such term or provision, and in the event she fails to timely do so, all amounts
which otherwise would be payable by Mannatech to Varner under this Agreement
shall cease and Mannatech shall be excused and have no further obligation for
payment of any further amounts to Varner under this Agreement or the Employment
Agreements. Provided, however, that notwithstanding such cessation of
Mannatech's obligations, Varner's Confidentiality, Non-Competition and Non-
Solicitation covenants contained in paragraphs 3 and 13(b) (i-iii), (c) and (d)
shall continue in full force and effect as specified in this Agreement. In
addition to the remedies referenced above, Mannatech may bring suit in a court
of competent jurisdiction to enforce any material term or provision of this
Agreement, and in the event said court determines that Varner has breached
and/or failed to perform any material term or provision of this Agreement,
damages and injunctive relief may be issued against Varner and Varner shall be
obligated to pay reasonable attorneys fees, costs and expenses incurred by
Mannatech.

     15.  Should Mannatech default in timely payment on the due date of any
payment or amount due under this Agreement, Varner shall give written notice of
such default to the persons specified in or pursuant to this Agreement to
receive notice on behalf of Mannatech. Mannatech shall have fifteen (15)
calendar days after the receipt of such a notice of default to cure any payment
default. Should Mannatech fail to cure any payment default within fifteen (15)
calendar days after such a payment default notice is so received, the entire
balance remaining due and payable to Varner under this Agreement shall be
accelerated and all amounts remaining unpaid under

                                    Page 14
<PAGE>

this Agreement by Mannatech to Varner shall become immediately due and payable.
After the due date, whether by acceleration or otherwise, unpaid payments then
due and payable by Mannatech to Varner shall accrue interest at the highest
lawful rate chargeable in the State of Texas. In the event that Varner brings
suit in a court of competent jurisdiction to enforce this Agreement and, after
trial is deemed by the Court to be the prevailing party in such litigation, she
shall be entitled to recover such payments and benefits required under this
Agreement and recover as damages from Mannatech, reasonable attorneys fees,
costs and expenses incurred in connection with the pursuit of such legal process
and/or lawsuit.

     16.  Mannatech releases Varner from any and all claims, causes of action,
losses, obligations, liabilities, damages, judgments, costs, expenses (including
attorneys fees) which arise out of actions taken by Varner while serving
Mannatech and acting in good faith, and which she had no reasonable cause to
believe the conduct was unlawful or illegal, including, but not limited to,
claims under federal, state or local constitution, statute, law, ordinance, or
regulation. In this regard, Varner shall be deemed to have acted in good faith
and/or with reasonable cause to believe her conduct was lawful and legal if she
acted in reliance on the advice, counsel or opinion of outside counsel to
Mannatech. However, Mannatech does not release its right to enforce the terms of
this Agreement.

     17.  If Varner or anyone acting on her behalf brings suit against Mannatech
seeking to declare any term of this Agreement void or unenforceable, and if one
or more material terms of this Agreement are ruled by a court to be void or
unenforceable or

                                    Page 15
<PAGE>

subject to reduction or modification, Mannatech may choose to cancel all of the
remaining terms of this Agreement and recover from Varner (or Varner's
successors or assigns) the value of anything paid by Mannatech in exchange for
this Agreement. If the Agreement is not canceled by Mannatech, then the
remaining terms of this Agreement, including any modification or reduction by
the court, shall continue in full force and effect.

     18.  Varner and Mannatech agree that neither Varner nor any of its officers
or directors will disparage the other. In respect to any inquiries from
individuals who are not employed with Mannatech concerning the termination of
the employment relationship between Varner and Mannatech, the Parties will
respond to the effect that "Deanne Varner resigned to pursue other business
ventures."

     19.  The Parties acknowledge that this Agreement has been drafted,
prepared, negotiated and agreed to jointly, with advice of each Party's
respective counsel, and to the extent that any ambiguity should appear, now or
at any time in the future, latent or apparent, such ambiguity shall not be
resolved or construed against either Party.

     20.  This Agreement shall not in any way be construed as an admission by
either Party of any acts of wrongdoing, violation of any statute, law or legal
or contractual right. Rather, Mannatech and Varner are willing to enter into
this Agreement described herein to definitively resolve once and forever this
matter, and to avoid the cost, expense and delay of litigation.

     21.  Varner and Mannatech represent and agree that they have thoroughly
discussed all aspects of this Agreement and the effect of same with their
attorneys,

                                    Page 16
<PAGE>

that they have had a reasonable time to review the Agreement, that they fully
understand all the provisions of the Agreement and are voluntarily entering into
this Separation Agreement and the Mutual General Release. Varner further
represents that she has not transferred or assigned to any person or entity any
claim involving Mannatech or any portion thereof or interest therein.

     22.  Each of the Parties agree to keep confidential the specific terms of
this Agreement, and shall not disclose the terms of this Agreement to any person
except the financial, tax and legal advisors of Varner and Mannatech (and the
Board of Directors of Mannatech) unless required to disclose same to others by
legal process, in which event the Party so ordered shall to the extent practical
under the circumstances first give notice to the other Party in order that such
other party may have an opportunity to seek a protective order. The Parties
shall cooperate with each other, should either decide to seek a protective order
with all costs and expenses being borne by the party seeking such order. Both
Parties shall abide by the final order, judgment, or decree of any court of
competent jurisdiction, administration or regulatory body regarding such
application for protective order. This Agreement may be disclosed or appended as
an exhibit to any securities filing required to be made by the Company, however,
after having been so disclosed or appended, Varner shall have no further duty of
confidentiality concerning this Agreement, as set forth in this paragraph.
Further, Varner may at any time disclose a copy of paragraphs 3, 11 and 13(b) of
this Agreement.

                                    Page 17
<PAGE>

     23.  All notices and other communications hereunder will be in writing. Any
notice or other communication hereunder shall be deemed duly given if it is sent
by registered or certified mail, return receipt requested, postage prepaid, and
addressed to the intended recipient as set forth:

     If to Varner:

          Ms. Deanne Varner
          4100 St. John's Drive
          Dallas, Texas 75205

     With copy to:

          Mark Shank, Esq.
          Clark West Keller, L.L.P.
          4800 Renaissance Tower
          Dallas, Texas 75270

     If to Mannatech:

          Mr. Robert M. Henry
          Mannatech Incorporated
          600 S. Royal Lane, Suite 200
          Coppell, Texas 75019

     With copy to:

          Jonathan Wilson, Esq.
          Haynes and Boone, LLP
          901 Main Street
          Suite 3100
          Dallas, Texas 75202

Any party may send any notice or other communication hereunder to the intended
recipient at the address set forth using any other means (including personal
delivery, expedited courier, messenger services, telecopy, telex, ordinary mail
or electronic mail), but no such notice or other communication shall be deemed
to have been duly given

                                    Page 18
<PAGE>

unless and until it is actually received by the intended recipient. Any party
may change the address to which notices and other communications hereunder are
to be delivered by giving the other party notice in the manner set forth herein.

     24.  This Agreement may be executed in multiple counterparts, whether or
not all signatories appear on these counterparts, and each counterpart shall be
deemed an original for all purposes. This Agreement shall be deemed performable
by all Parties in Dallas County, Texas and the construction and enforcement of
this Agreement shall be governed by Texas law without regard to its conflicts of
law rules.

     25.  Varner has been given a period of 21 days from the Effective Date to
review and consider this Agreement before signing it. She may use as much of the
21-day period as she wishes before signing and she is encouraged to consult with
her attorney, Mark Shank, or any other attorney of her choosing, before signing
this Agreement. Varner understands that whether or not to consult with an
attorney is her decision. Varner may revoke this Agreement within 7 (seven) days
after signing it. Revocation is only effective if Varner delivers a written
notice of revocation to Mannatech, Inc. c/o Robert Henry, Chief Executive
Officer, 600 South Royal Lane, Suite 200, Coppell, Texas 75019, within seven (7)
days after signing the Agreement. This agreement is subject to review and
approval by the Board of Directors and its various committees.

     I ACKNOWLEDGE THAT I HAVE CAREFULLY READ THE FOREGOING AGREEMENT, THAT I
UNDERSTAND ALL OF ITS TERMS, AND THAT I AM ENTERING INTO IT VOLUNTARILY.

                                    Page 19
<PAGE>

     I FURTHER ACKNOWLEDGE THAT I AM AWARE OF MY RIGHTS TO REVIEW AND CONSIDER
THEIR AGREEMENT FOR 21 DAYS AND TO CONSULT WITH AN ATTORNEY ABOUT IT, AND STATE
THAT BEFORE SIGNING THEIR AGREEMENT, I EXERCISE THESE RIGHTS TO THE FULL EXTENT
THAT I DESIRED.

                                    Page 20
<PAGE>

AGREED TO:



/s/ DEANNE VARNER                      Date:   May 2, 2001
-----------------------------------         -----------------------------------
DEANNE VARNER


STATE OF Texas

COUNTY OF Dallas

This instrument was acknowledged before me on this 2nd day of May 2001, by
DEANNE VARNER.


[NOTARY SEAL]                          /s/ GILDA M. DANIEL
                                       ----------------------------------------
                                       Notary Public in and for the State of TX

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MANNATECH, INC.



By: /s/ ROBERT M. HENRY                Date: May 2, 2001
    ------------------------------          ------------------------------
Title: Chief Executive Officer
      ----------------------------


STATE OF TEXAS

COUNTY OF DALLAS

     Before me, a Notary Public, on this day personally appeared Robert M.
Henry, known to me to be the person and officer whose name is subscribed to the
foregoing instrument and acknowledged to me that the same was the act of Robert
M. Henry, and that he has executed the same on behalf of said corporation for
the purposes and consideration therein expressed, and in the capacity therein
stated.

     Given under my hand and seal of office this 2nd day of May, 2001.

[NOTARY SEAL]                        /S/ CAROLYN D. STUART
                                     ----------------------------------------
                                     Notary Public in and for the State of Texas

(PERSONALIZED SEAL)

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                                Attachment "A"

                            GENERAL COUNSEL RESIGNS

     Coppell, Texas - - Mannatech, Inc. has announced the resignation of Deanne
     Varner, Senior Vice President and General Counsel, effective April _______,
     2001.* Ms. Varner intends to pursue and develop private ventures.

     Mannatech, Inc. develops proprietary nutritional supplements and topical
     products, which it sells through a network marketing system through the
     United States and internationally.


*Reference Separation Date in paragraph 1 of this Agreement.