TRT bloodwork interpretation: what the markers actually mean

What did @t_nutrition_fitness actually say?

The creator shared recent bloodwork and walked through several hormone markers. The core claims: total testosterone came back high, but high SHBG makes that testosterone "less usable," blunting muscle-building potential. They attributed the elevated testosterone to a hair loss treatment (a DHT blocker, almost certainly finasteride or dutasteride). They also flagged elevated AST and skipped rest days as the likely cause. LH, FSH, and lipids were described as normal. They're working with a Merrick Health specialist and disclosed that Merrick sponsored the bloodwork.

To their credit, the creator explicitly said they're not the foremost expert on bloodwork and invited correction. That's a reasonable disclaimer for a 83K-view TikTok on hormone biology.

Does the science back this up?

The SHBG-free testosterone relationship is real and well-documented, but the claim that high total testosterone "won't make much of a difference" for muscle building oversimplifies a genuinely contested area. The DHT-to-testosterone link via 5-alpha reductase inhibitors is also real, but the size of that testosterone increase is usually modest.

SHBG binds testosterone with high affinity, leaving only 1-3% of circulating testosterone in its free, bioavailable form (Vermeulen et al., 1999, Journal of Clinical Endocrinology and Metabolism). When SHBG is elevated, free testosterone drops even if total testosterone looks normal or high. That part the creator got right. However, the relationship between free testosterone and hypertrophy outcomes in otherwise healthy men is less straightforward than "high SHBG equals less muscle." A 2013 study by Bhasin et al. in the Journal of Clinical Endocrinology and Metabolism showed hypertrophy correlates more strongly with total testosterone across a wide dose range, with free testosterone playing a role mainly at extremes. The creator's framing isn't wrong, but it's incomplete.

On finasteride and testosterone: 5-alpha reductase inhibitors reduce DHT by 60-70% and can cause a compensatory modest rise in testosterone, typically 10-15% (Guess et al., 1993, Journal of Urology). A dramatic testosterone elevation from finasteride alone would be unusual and warrants investigation.

What did they get wrong (or right)?

They got the SHBG mechanism mostly right. Where the reasoning gets shaky is the confident attribution of a "quite high" testosterone reading solely to a hair treatment. Finasteride and dutasteride do raise testosterone modestly, but if the reading is significantly above the 700-900 range the creator says is their baseline, a single drug explanation may not cover it. Other factors, including assay variability, hydration status, time of draw, and stress hormones, all affect results.

The AST-exercise connection is accurate. Resistance training elevates AST and ALT due to skeletal muscle breakdown, not just liver stress. A 2020 review by Pettersson et al. in the British Journal of Sports Medicine confirmed that AST can spike significantly after heavy training, which is why clinical guidelines recommend drawing liver enzymes at least 48 hours post-exercise. The creator's self-diagnosis here is actually reasonable.

The SHBG-as-free-testosterone-limiter framing, while directionally correct, should not be taken as a reason to self-treat or chase lower SHBG. Elevated SHBG has associations with cardiovascular protection in some populations (Ding et al., 2009, JAMA Internal Medicine).

What should you actually know?

A few things worth knowing if you're tempted to read your own bloodwork the same way. First, total testosterone alone is nearly meaningless without free testosterone, SHBG, albumin, and ideally calculated bioavailable testosterone. Second, the timing of your blood draw matters. Morning draws (7-10 AM) typically capture peak testosterone. Training the day before can skew AST, ALT, and creatine kinase. Third, DHT blockers carry a real side effect profile that goes beyond hormone numbers, including potential effects on libido, mood, and sexual function, and those deserve a conversation with a licensed provider, not just a bloodwork sponsor.

The creator is meeting with a Merrick Health specialist, which is the right move. Interpreting hormone panels requires clinical context that a TikTok cannot provide. If your numbers look off, the answer is a conversation with a physician, not a comment section.