Intervention: Testosterone
Trial phase: Phase 1
ATC code: G03BA03 | G03EA02
SMILES: [H][C@@]12CCC3=CC(=O)CC[C@]3(C)[C@@]1([H])CC[C@]1(C)[C@@H](O)CC[C@@]21[H]
Sex: Male
Age groups: Adult | Older Adult
Healthy volunteers: Accepts Healthy Volunteers
Participants at risk: 29
Group description: No deodorant or antiperspirant. A single 30-milligram (mg) dose of testosterone 2% solution applied topically to each unshaved axilla.
Eligibility criteria:
Inclusion Criteria:

Are overtly healthy males, as determined by medical history and physical examination
Agree to use a reliable method of birth control (for example, condom or vasectomy) during the study and for 1 month following the last dose of testosterone
Have a total testosterone level <400 nanograms per deciliter (ng/dL) based on local laboratory result
Have a hemoglobin ≥12 grams per deciliter (g/dL) at screening and, if the participant takes a break from the study, at the re-test
Weigh at least 60 kilograms (kg)
Have venous access sufficient to allow for blood sampling
Are reliable and willing to make themselves available for the duration of the study and are willing to follow study procedures
Have given written informed consent approved by Eli Lilly and Company (Lilly) and the ethical review board (ERB) governing the site

Exclusion Criteria:

Use any topical testosterone replacement therapy within the 2 weeks prior to randomization through the last dosing period, except for use of testosterone solution as directed by study procedures
Use parenteral testosterone replacement (testosterone enanthanate, testosterone cypionate) within the 30 days prior to screening. Use long-acting intramuscular testosterone undecanoate 6 months prior to screening, or use of testosterone pellets 12 months prior to screening
Have a body mass index >35 kilograms per square meter (kg/m^2)
Have a significant history of allergy and/or sensitivity to the drug products or excipients, including any history of sensitivity to testosterone
Currently use any medications, herbal, and/or nutritional supplements that can interfere with testosterone
Have a dermatologic condition in the underarm area that might interfere with testosterone absorption (for example, eczema) or be exacerbated by topical testosterone replacement therapy
Have a history or presence of/significant history of or current cardiovascular, respiratory, hepatic, renal, endocrine, hematological, or neurological disorders constituting a risk when taking the study medication of that could interfere with the interpretation of the data
Have had lymphoma, leukemia, or any malignancy within the past 5 years except for basal cell or squamous epithelial carcinomas of the skin that have been resected with no evidence of metastatic disease for 3 years
Have an abnormal prostate-specific antigen (PSA) test result
Have known allergies to testosterone solution, related compounds or any components of the formulation, or history of significant atopy
Have an abnormality in the 12-lead electrocardiogram (ECG) that, in the opinion of the investigator, increases the risks associated with participating in the study
Have an abnormal blood pressure as determined by the investigator
Regularly use known drugs of abuse and/or show positive findings on urinary drug screening
Show evidence of hepatitis B and/or positive hepatitis B surface antigen
Show evidence of hepatitis C and/or positive hepatitis C antibody
Show evidence of human immunodeficiency (HIV) infection and/or positive human HIV antibodies
Are participants who have previously completed or withdrawn from this study or any other study investigating testosterone
Are currently enrolled in, or discontinued within the last 30 days from, a clinical trial involving an investigational product or nonapproved use of a drug or device (other than the investigational product used in this study), or are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study
In the opinion of the investigator or sponsor, are unsuitable for inclusion in the study
Have shaved the axillae within 3 months of screening