AndroGel: Medical Testosterone Gel — Use and Transfer Risk

AndroGel is a testosterone gel applied to the skin once daily, and one of the most prescribed forms of replacement therapy for people who want to avoid injections. It also carries a warning unique among testosterone products: transfer to children and women through skin contact, with documented cases of virilisation in children who never took the drug. This guide covers how it's absorbed, the approved indications, the application rules that reduce the risk, and the monitoring and side effects.

What is AndroGel?

AndroGel is a topical testosterone preparation — an alcohol-based gel applied to the skin once a day. It comes in two strengths, 1% and 1.62%, in a metered pump delivering 20.25 mg of testosterone per actuation, or in single packets of 20.25 or 40.5 mg.

It is a prescription medicine and a controlled substance (Schedule III in the US). The active ingredient is testosterone itself — no ester, no synthetic derivative — and the whole difference lies in delivery: slow absorption through skin rather than an oil depot in muscle.

How transdermal absorption works

The gel's alcohol base evaporates after application, leaving testosterone in the stratum corneum, which acts as a reservoir releasing hormone gradually into the bloodstream across the day. The result is a steadier curve than long-acting injections: no sharp peak, no deep trough, just a fairly level daily profile closer to natural rhythm.

Two costs come with that stability: daily adherence — a missed dose shows up quickly — and absorption variability between individuals, depending on skin thickness, application area, sweating and bathing. Some patients never reach therapeutic levels on gel despite perfect adherence, and they need a different formulation, decided medically.

Approved indications and their limits

The approved indication is replacement therapy in adult males for conditions associated with deficiency or absence of endogenous testosterone:

• Primary hypogonadism: testicular failure from cryptorchidism, bilateral torsion, orchitis, Klinefelter syndrome, orchiectomy, or damage from chemotherapy or heavy metals.
• Hypogonadotropic hypogonadism: gonadotropin deficiency or hypothalamic-pituitary injury.

The label also states explicit limitations of use that many people overlook: safety and efficacy have not been established in so-called "age-related hypogonadism," nor in males under 18. Using it simply for low energy with age is not an evidence-supported use.

Contraindications: male breast carcinoma, known or suspected prostate cancer, and women who are pregnant or breastfeeding — testosterone can harm the fetus.

The boxed warning: transfer through skin contact

This is the risk unique to gel among all testosterone forms, and it carries a boxed (black box) warning the FDA required in 2009 after reports of children exposed through contact.

What postmarketing reports documented in secondarily exposed children:

• Enlargement of the penis or clitoris.
• Premature development of pubic hair.
• Increased erections and libido, and aggressive behaviour.
• Advanced bone age.

In most cases the signs regressed once exposure stopped, but in some, enlarged genitalia did not fully return to age-appropriate size and bone age remained advanced. Some children underwent invasive diagnostic procedures before the cause was identified. In exposed women, signs of virilisation were reported including changes in body hair distribution and a significant increase in acne.

The decisive point: the child took no drug at all — being carried against an unwashed, uncovered shoulder or arm is enough. Most documented cases involved failure to follow the usage instructions.

Application rules that reduce the risk

The label requires strict adherence to the following:

• Application site: shoulders and upper arms only for the 1.62% strength — within the area a short-sleeve t-shirt covers. The 1% strength also permits the abdomen.
• Never apply to the genitals.
• Wash hands with soap and water immediately after applying.
• Cover the site with clothing once the gel has dried.
• Wash the site thoroughly with soap and water before any anticipated direct skin-to-skin contact.
• If someone else contacts an unwashed or uncovered site, wash their skin with soap and water right away.
• Wait the interval the label specifies before showering or swimming, so the drug isn't removed before absorption.

And if any sign of virilisation appears in a child or woman in the household: stop the drug and see a doctor until the cause is identified. That is an explicit label instruction, not an excess of caution.

Side effects and lab monitoring

Risks the label states explicitly

• Polycythaemia: a rising haematocrit may require lowering or stopping the drug; haematocrit is checked before starting and periodically after.
• Venous thromboembolism: deep vein thrombosis and pulmonary embolism have been reported with testosterone products; suspicious symptoms need immediate evaluation.
• Cardiac: some postmarketing studies have shown increased risk of myocardial infarction and stroke with replacement therapy.
• Worsening benign prostatic hyperplasia, with prostate cancer risk monitoring.
• Oedema with or without congestive heart failure, particularly in cardiac, renal or hepatic disease.
• Sleep apnoea in those with risk factors.
• Azoospermia: a known consequence of exogenous androgen administration.

Other effects

• Local skin reactions: redness, itching, dryness or acne at the application site.
• Mood changes, headache, increased libido.
• Gynecomastia from aromatisation to oestrogen.

Monitoring

Testosterone levels (usually measured after several weeks at steady state), haematocrit and haemoglobin, lipid profile, liver function, and PSA with prostate risk assessment — targeting the mid-normal range rather than the top.

Fertility

Like any exogenous testosterone, AndroGel suppresses LH and FSH, removing the intratesticular signalling sperm production depends on, and azoospermia can result — stated explicitly among the label warnings.

Anyone planning children in the near term should discuss alternatives with a doctor before starting, since drugs exist that raise testosterone without shutting down fertility. Recovery after stopping is usually possible but takes months.

Gel versus injection

Neither form is universally better: gel suits people who fear needles or want steadier levels and the ability to stop quickly; injections suit households with small children, or men who absorb gel poorly. It's a medical decision based on the case, the labs and the home situation.

Non-medical use and the stacking question

AndroGel is rarely used for performance or muscle for practical reasons: the quantity needed to push levels above the normal range is large and costly, absorption is limited by skin area, and the risk of transferring the drug to household members persists the entire time.

As for "stacking" — using more than one hormonal compound at once — we cover it as a phenomenon whose risks need to be understood and provide no doses or combinations: risks accumulate on lipids, haematocrit, blood pressure, the heart and the hormonal axis; attributing any symptom to its source becomes impossible; and no clinical trials on combinations exist. With gel specifically there's an added responsibility: every increase in the amount applied expands the contaminated skin area and the chance a child or woman at home is exposed.

Detection in doping tests

Testosterone is prohibited in and out of competition under the World Anti-Doping Agency list, regardless of the route of administration. Because it's endogenous, detection relies on the athlete biological passport and the testosterone-to-epitestosterone ratio, with carbon isotope ratio mass spectrometry (IRMS) settling suspicious cases. A topical form offers no concealment from testing.

Legal status and counterfeits

In Oman and across the GCC, testosterone in every form is a scheduled prescription-only substance; possessing, selling or importing it without a prescription is a legal offence.

Unbranded "testosterone gels" of unknown concentration circulate online, and with a topical product stored at home and applied daily, unknown concentration means both an unknown dose and an unknown transfer risk for everyone in the household.

Common myths

"Gel is milder than injections": the active substance is the same testosterone; suppression, polycythaemia and the effect on fertility all apply regardless of route.

"Casual contact transfers nothing": the documented paediatric cases arose from contact with unwashed or uncovered skin, and some effects did not fully reverse.

"I'll apply more for a stronger effect": absorption is limited by skin area; more gel raises contamination and transfer risk more than it raises blood levels.

"Suitable for any tired man getting older": the label states plainly that safety and efficacy are not established in age-related hypogonadism.

"No needles means no blood work": haematocrit is checked before starting and during treatment, with PSA and lipids monitored the same as any other form.

Related reading

Frequently asked questions

Sources

• AndroGel 1.62% — FDA Prescribing Information with boxed warning
• AndroGel 1% — FDA label (accessdata)
• AndroGel 1.62% — original FDA approval labeling (NDA 022309)
• AndroGel — Warnings and Precautions, secondary exposure (medlibrary)
• Bhasin et al. — Testosterone Therapy in Men With Hypogonadism: Endocrine Society Clinical Practice Guideline (2018)