Topical TRT: Gels, Creams, and Patches Compared — What Works Best

Nearly 70% of initial testosterone prescriptions in the United States are for a topical formulation. Gels and patches dominate clinical practice because they're non-invasive, easy to titrate, and avoid the peaks and troughs associated with injectable esters. But the absorption profile of topical testosterone is messy, variable, and highly sensitive to application technique, skin condition, and product formulation. Most men on topical TRT never reach stable physiologic levels — not because the drug is ineffective, but because the delivery method requires more active management than it's marketed to suggest.

How Topical Testosterone Works

Topical formulations deliver testosterone through the stratum corneum into dermal capillaries, where it enters systemic circulation. Unlike injections, which depot testosterone ester in muscle and release it over days, topical products require daily application and produce a pharmacokinetic profile that rises within 2-4 hours, peaks around 8-12 hours, and then declines. Absorption rates vary significantly between individuals — some men absorb only 9% of the applied dose, while others absorb over 40%. This sevenfold variability is why two men using the same product at the same dose can have wildly different trough levels.

Several factors influence transdermal absorption. Skin thickness matters — the scrotal skin is thinner and more absorptive than shoulder or thigh skin, which is why some newer formulations recommend specific application sites. Skin integrity matters — dry, cracked, or inflamed skin absorbs differently than healthy skin. Heat matters — showering before application opens pores and increases absorption, while applying immediately after swimming in cold water can reduce it. The ethanol-based vehicle in gels also affects penetration, and the specific alcohol-to-water ratio differs between brands.

FDA-Approved Gels

AndroGel 1.62% is the most widely prescribed testosterone gel in the United States. It comes in a pump delivery (20.25 mg per actuation) or packets (12.5 mg, 25 mg). The standard starting dose is 40.5 mg (two pump actuations) applied to the shoulders and upper arms once daily. The product label specifies application to clean, dry skin and recommends washing hands thoroughly and allowing the application site to dry before covering with clothing. Patients should shower or swim at least 6 hours after application to prevent washing off unabsorbed product.

AndroGel's absorption variability is well-documented. A pharmacokinetic analysis found that 30-50% of men require dose escalation from the starting 40.5 mg to achieve serum testosterone levels within the reference range (300-1,000 ng/dL). Some clinics proactively start at 60.75 mg (three pump actuations) based on baseline body weight and testosterone deficiency severity.

Fortesta (testosterone gel 2%) is a metered-dose gel applied to the front and inner thighs. Each pump actuation delivers 10 mg of testosterone, with a recommended starting dose of 40 mg (four actuations) daily. Fortesta uses a different vehicle than AndroGel — it contains isopropyl alcohol, propylene glycol, and carbomer, which creates a different absorption profile. Some patients who experience skin irritation with AndroGel tolerate Fortesta better, and vice versa. The thigh application site is less likely to result in secondary exposure to partners compared to shoulder application.

Testim 1% is similar in concentration to the older AndroGel 1%, delivering 50 mg per 5 g tube. It uses a different solvent system and is associated with a somewhat higher risk of skin reactions in clinical trial data. The clinical efficacy is comparable to other 1% gels, but the cost is often higher, and many clinics reserve Testim for patients who have tried AndroGel or Fortesta without achieving adequate levels or without tolerating those products.

Voelzo (testosterone gel 1.62%) is marketed in a metered-dose topical pump similar to AndroGel but with minor formulation differences. It delivers 20.25 mg of testosterone per actuation. Clinical bioequivalence studies showed comparable pharmacokinetics to AndroGel 1.62%. Voelzo is typically selected based on formulary availability and cost rather than clinical differentiation.

TestoGel and International Formulations

TestoGel 1.62% (Bayer) is the dominant topical testosterone product in European markets. It contains 16.2 mg of testosterone per gram of gel, delivered in 2.5 g sachets (40.5 mg per sachet). The recommended dose is one sachet daily, with titration up to two sachets if needed. TestoGel is not FDA-approved but is available in the UK, France, Germany, and most EU countries. Its pharmacokinetics are nearly identical to AndroGel 1.62%, and European endocrinology guidelines reference it as the first-line topical option.

Patches

Androderm is the only FDA-approved testosterone patch still widely available. It delivers 4 mg of testosterone over 24 hours per patch, with a standard starting dose of one or two patches applied nightly. Patches produce a steadier pharmacokinetic profile than gels because the drug is released continuously from the transdermal delivery system rather than being absorbed in a single-bolus fashion. In theory, this should produce more stable trough levels. In practice, patches are plagued by adherence issues.

Skin irritation at the application site is the most common adverse event with Androderm, affecting up to 35% of users in clinical trials. The irritation is not just discomfort — it can change absorption over time as skin thickens in response to chronic adhesive exposure. Patients often rotate sites (abdomen, back, upper arms, thighs) to mitigate this, but the rotation itself introduces variability in absorption rates because different skin regions have different permeability.

Clinically, patches are a reasonable option for men who are non-compliant with daily gel application or who work in environments where secondary exposure via skin contact is a concern (contact sports, childcare, shared living spaces). But the real-world discontinuation rate for patches is higher than for gels due to skin reactions and the social awkwardness of visible patch placement.

Compounded Testosterone Creams

Compounded testosterone creams are not FDA-approved but are prescribed by telehealth clinics, men's health practices, and compounding pharmacies. These products use testosterone USP powder in a transdermal base — often a combination of lecithin, isopropyl palmitate, purified water, and gelling agents. The lack of FDA approval means these products are not subject to the same rigorous pharmacokinetic testing as branded gels. Absorption can be unpredictable, and batch-to-batch consistency varies.

Some compounding pharmacies add penetration enhancers like dimethyl sulfoxide (DMSO) or propylene glycol to increase absorption. This is a double-edged sword — the same enhancement that improves bioavailability also increases the risk of secondary exposure and makes dosing calculations less reliable. Men using compounded creams should request product certificates of analysis from their pharmacy and should have their testosterone levels checked more frequently during the titration phase than men on branded products.

The cost advantage of compounded creams is real. Where branded gels can cost $20-45 per month with insurance (or $400-600 cash price), compounded creams often run $30-80 per month cash. For men paying out of pocket, this is a meaningful difference. The tradeoff is the absence of pharmacokinetic validation and the need for a clinician comfortable managing a non-standard product.

Secondary Exposure Risk

All topical testosterone formulations carry a risk of secondary exposure to women, children, and pets through skin-to-skin contact. The FDA has issued multiple warnings about this, particularly regarding virilization in children exposed to a parent's application site. Reported effects include premature puberty in boys, clitoral enlargement and hair growth in girls, and behavioral changes including increased aggression.

Prevention strategies are straightforward but require consistent compliance: apply the product to areas covered by clothing (shoulders and upper arms under a t-shirt), wash hands thoroughly with soap and water after application, and wash the application site before anticipated skin-to-skin contact. If a partner has had direct contact with the application site, they should wash the contacted area with soap and water as soon as possible.

Patch users have a different secondary exposure profile — the testosterone is contained within the patch delivery system and is not present on the skin surface. However, if a patch falls off or is improperly applied, the adhesive side contains residual testosterone. Patches should be stored out of reach of children and disposed of by folding the used patch in half (adhesive to adhesive) before throwing it away.

Optimizing Your Topical TRT Protocol

If you're on a topical formulation and your levels are inconsistent despite dose adjustments, consider these evidence-based optimization strategies:

Application timing: Apply at the same time daily, ideally in the morning, to align with your natural circadian testosterone rhythm and make blood draw timing consistent. If you apply at night and test in the morning, you're measuring trough levels 12+ hours post-application, which may underrepresent your average exposure.

Application site: Follow the product label precisely. AndroGel is approved for shoulders and upper arms only — applying it to the abdomen or thighs off-label changes absorption in ways that haven't been studied. Fortesta is approved for anterior and inner thighs only. Scrotal application (which produces 2-8x higher absorption due to thinner skin and higher density of transdermal channels) is not recommended for branded gels due to the risk of supraphysiologic levels.

Showering timing: Wait at least 6 hours after application before swimming or showering. A pharmacokinetic sub-study of AndroGel found that showering at 2 hours post-application reduced testosterone bioavailability by approximately 10%. If your routine requires morning gym sessions with showers, consider applying the gel at night and sleeping with long sleeves to prevent secondary exposure during sleep.

Blood draw timing: The Endocrine Society guidelines recommend measuring serum testosterone at least 4 hours after topical application. If you apply at 8 AM, your blood draw should be no earlier than noon. Drawing at trough (12-24 hours post-application) will give you a lower value that doesn't reflect your average exposure and may trigger unnecessary dose escalation.

Consistency of product: Do not switch between gel and patch or between different gel brands without informing your prescriber. Each product has a different pharmacokinetic profile, and your dose in mg of testosterone applied does not translate directly across products. A man doing 60.75 mg of AndroGel may need a completely different dose on Fortesta or TestoGel to achieve the same serum levels.

When Topical TRT Fails

Approximately 10-15% of men cannot achieve adequate serum testosterone levels on topical formulations, even at the maximum recommended doses. This is not treatment failure — it's a pharmacokinetic reality of transdermal delivery. Men in this category should be transitioned to injectable testosterone, which bypasses the stratum corneum entirely and produces more predictable serum levels. Subcutaneous injections using insulin needles are increasingly the preferred alternative in this population, as they allow self-administration with less injection-site discomfort than intramuscular delivery.

Another group of men who should avoid topical TRT includes those with extensive skin conditions — psoriasis, eczema, or dermatitis affecting the approved application sites — that could alter absorption or exacerbate irritation. These patients are better served by non-topical delivery methods.

Topical testosterone is an effective, convenient, and widely used TRT delivery method when used correctly. The key word is "correctly" — application technique, timing, blood draw scheduling, and product consistency all matter as much as the dose itself. Men on topical TRT who are experiencing persistent symptoms or suboptimal lab values should review their application technique with their clinician before assuming the dose is inadequate. In many cases, the problem isn't how much testosterone they're applying — it's how, where, and when they're applying it.