Finasteride and testosterone gel: what the combo actually does

What did @gloomyonionboy actually say?

They were applying a full tube of testosterone gel, which pushed their levels to "a thousand 300 in something" ng/dL. After cutting to half a tube, levels dropped to 704 ng/dL. They also report less greasiness, less emotional reactivity, some shoulder acne, and a barely-visible potential mustache. They're on finasteride, which they acknowledge likely limits body hair growth.

The creator also describes a notable geographic shift: after moving from California to the South, they're finding their doctors "way more respectful" and are still getting care, though hormones aren't covered by insurance. They frame reduced crying as an estrogen-related change, attributing it to their testosterone levels coming up.

Does the science back this up?

Mostly, yes. The dose-to-level relationship they describe is roughly consistent with what pharmacokinetic data shows for topical testosterone, though gel absorption is notoriously variable between individuals.

The normal reference range for total testosterone in adult males is generally cited as 300 to 1,000 ng/dL, with most clinical guidelines targeting 400 to 700 ng/dL for TRT (Bhasin et al., 2018, Journal of Clinical Endocrinology and Metabolism). At 1,300 ng/dL, they were genuinely supraphysiologic. The symptoms they describe at that level, oiliness, increased libido, hunger, are consistent with androgen excess. Dropping to 704 ng/dL puts them in the upper-normal physiological range, which is a reasonable target for many patients.

On the acne point: shoulder acne appearing while facial skin improved is plausible. Sebaceous gland density varies by body region, and androgen receptor sensitivity differs accordingly (Chen et al., 2002, Journal of Investigative Dermatology).

What did they get wrong (or right)?

They got quite a bit right. The relationship between supraphysiologic testosterone and oiliness, libido spikes, and appetite is well-documented. Their self-titration logic, that halving the dose approximately halved the level, happened to work out, but this is not a reliable rule. Gel absorption varies significantly based on skin site, sweating, bathing habits, and individual transdermal uptake. The Endocrine Society explicitly warns against patient-directed dose adjustments for this reason.

The finasteride-body hair connection is accurate. Finasteride inhibits 5-alpha reductase, which converts testosterone to dihydrotestosterone (DHT). DHT is the primary driver of body and facial hair growth in androgen-sensitive follicles (Kaufman et al., 1998, Journal of the American Academy of Dermatology). So yes, being on fin genuinely does blunt that effect.

The emotional changes they attribute to estrogen reduction deserve scrutiny. Testosterone aromatizes to estradiol, and at 1,300 ng/dL total T, estradiol levels were likely also elevated. Reduced crying could reflect lower estradiol, but it could also reflect a general hormonal stabilization. Attributing it cleanly to estrogen alone is an oversimplification, though not a wrong instinct.

What should you actually know?

A few things worth flagging for anyone watching this and thinking about their own protocol. First, 1,300 ng/dL is not a safe cruising altitude. Sustained supraphysiologic testosterone increases erythrocytosis risk, meaning elevated red blood cell count, which is a real cardiovascular concern (Coviello et al., 2008, Journal of Clinical Endocrinology and Metabolism). This is why hematocrit monitoring is standard of care on TRT, not optional.

Second, self-adjusting a gel dose based on feel is common in patient communities, but labs should be driving those decisions. The creator got lucky that their rough math aligned with their bloodwork. That is not always how it goes.

Third, the "tea sponge" comment, where they suggest they absorb testosterone more efficiently than average, is actually a real phenomenon. Some individuals show dramatically higher serum levels from identical topical doses. This is not well-predicted by any simple clinical marker, which is why follow-up testing after dose changes matters.

• Target testosterone range for most TRT patients: 400 to 700 ng/dL (Bhasin et al., 2018)
• Finasteride meaningfully reduces DHT-dependent hair changes, the creator is correct here
• Shoulder acne during TRT is common and does not necessarily mean total levels are too high
• Dose adjustments should follow lab results, not symptom estimation alone