World Trade Center East 


   


 Two Seaport Lane 


   


 Suite 300 


   


 Boston, MA 02210-2028 


   


 (617) 946-4800 


   


 fax (617) 946-4801 


   


 www.seyfarth.com 


   


 May 5, 2017 


   


 Via
E-Mail 


   


 Oxygen Therapy, Inc. 


 233 Needham Street, Suite 300 


 Needham, MA 02464 


   


	   	 Re: 	 Oxygen Therapy,
    Inc. - Registration Statement on Form S-1 - Registration No. 333-214306 


   


 Dear Ladies and Gentlemen: 


   


 We have acted as counsel
to Oxygen Therapy, Inc., a Delaware corporation (the “Company”), in connection with the preparation and filing by
the Company with the Securities and Exchange Commission of a Registration Statement on Form S-1 (the “Registration Statement”),
under the Securities Act of 1933, as amended (the “Securities Act”). Such Registration Statement relates to the registration
for sale by the Company of 19,081,038 shares (the “Shares”) of common stock, par value $0.001 per share, of the Company
(the “Common Stock”) and the registration for resale by certain stockholders of the Company of 918,962 shares of Common
Stock (the “Selling Stockholder Shares, including 460,831 shares (the “Warrant Shares”) issuable upon the exercise
of outstanding warrants (the “Warrants”). 


   


 Collectively, the Shares
and the Selling Stockholder Shares are referred to herein as the “Securities.” 


   


 The Shares are to be
offered by the Company in a best efforts, direct public offering without any involvement of underwriters, as described in the
Registration Statement. In connection with the Registration Statement, we have examined and relied upon copies of such documents
and instruments that we have deemed necessary for the expression of the opinions contained herein. In our examination of these
documents, we have assumed, without independent investigation, the genuineness of all signatures, the legal capacity of all individuals
who have executed any of the documents, the authenticity of all documents submitted to us as originals and the conformity to the
original documents of all copies. 




   




    	 	 	 



    	 		 



    


   





 Oxygen Therapy, Inc. 


 May 5, 2017 


 Page 2 


   


 Based upon the foregoing
examination, we are of the following opinions: 


   


 1.     The
Shares, when sold pursuant to and in accordance with the Registration Statement and the documents described therein, will be duly
authorized, validly issued, fully paid and non-assessable shares of Common Stock of the Company. 


   


 2.     The
Selling Stockholder Shares, other than the Warrant Shares, are duly authorized, validly issued, fully paid and non-assessable
shares of Common Stock of the Company. 


   


 3.     The
Warrant Shares will be duly authorized, validly issued, fully paid and nonassessable when delivered and paid for upon exercise
of the Warrants in accordance with the terms of the Warrants. 


   


 The opinions expressed
herein are limited to the federal securities laws of the United States of America and the corporate laws of the State of Delaware
and we express no opinion as to the effect on the matters covered of the laws of any other jurisdiction. We hereby consent to
the filing of this opinion as an exhibit to the Registration Statement as it may be amended from time to time. We also consent
to the reference to this firm under the heading Legal Matters in the prospectus which forms a part of the Registration Statement.
In giving this consent, we do not admit that we are within the category of persons whose consent is required under Section 7
of the Securities Act or the rules and regulations of the Securities and Exchange Commission promulgated thereunder. 




   





	   	 Very
                                         truly yours, 

        

	   	   
	   	 Seyfarth
    Shaw LLP 
	   	   
	   	 /s/ Seyfarth Shaw LLP 







   


 MAK