Does injection frequency on TRT actually change your outcomes?

What did @trtover40 actually say?

The creator switched from three injections per week to every other day, kept the same weekly dose, and noticed a libido improvement. His explanation: more frequent injections may shift the ratio of bound to free testosterone without touching total levels. He frames this through a taxi analogy, where SHBG is the taxi trapping testosterone, and free testosterone is what actually does the work. It is a clean, accessible explanation for a genuinely complicated pharmacological idea.

To his credit, he is not selling a dose increase or a new compound. He is arguing that delivery mechanics matter independently of quantity. That is a more sophisticated point than most TRT content on this platform bothers to make, and it deserves a serious look rather than a reflexive dismissal.

Does the science back this up?

Mostly, yes, but with important caveats. The core claim, that injection frequency can influence free testosterone and SHBG dynamics without changing weekly dose, has biological plausibility. Testosterone cypionate and enanthate create supraphysiological peaks after injection, and those peaks can transiently suppress SHBG through hepatic mechanisms. More frequent, smaller injections produce shallower peaks and more stable troughs.

Rupesinghe et al. (2021, Andrology) found that shorter injection intervals produced more stable serum testosterone with less peak-to-trough variability. Separately, research by Winters et al. (1998, Journal of Clinical Endocrinology and Metabolism) established that SHBG levels are influenced by testosterone exposure patterns, not just absolute levels. However, the direct claim that frequency shifts the bound-to-free ratio in a clinically meaningful way for all men is less firmly established in controlled trials. Most of the evidence is observational or mechanistic, not randomized. The creator is on solid theoretical ground but is presenting inference as settled fact.

What did they get wrong or right?

The taxi analogy is actually pretty good. SHBG does bind testosterone with high affinity, rendering it biologically inactive for most tissue purposes, while free testosterone and albumin-bound testosterone are the fractions that cross cell membranes and activate androgen receptors. The analogy captures this without significant distortion. Credit where it is due.

Where he oversimplifies: the claim that two men with identical total testosterone levels can feel completely different is accurate, but SHBG is only one variable. Sex hormone-binding globulin levels vary by obesity, thyroid function, insulin sensitivity, liver health, and genetic polymorphisms in androgen receptors. His framing implies that frequency manipulation is the lever to pull, but for some men the limiting factor is receptor sensitivity, not SHBG binding. He also presents his personal anecdote, one guy, one switch, one subjective outcome, as evidence of a mechanism. That is not how causation works. Libido changes on TRT are influenced by sleep, stress, estradiol levels, and psychological expectation. He experienced something real, but his explanation may not be the right one.

What should you actually know?

Injection frequency is a legitimate variable that clinicians do adjust, but it is not a universal optimization lever. If your SHBG is already low or in the normal range, shifting from three times per week to every other day is unlikely to produce dramatic changes in free testosterone. The men most likely to benefit from frequency adjustments are those with elevated SHBG who are already experiencing suboptimal response at a stable dose.

Free testosterone is also harder to measure accurately than this video implies. Equilibrium dialysis is the gold-standard method, but most labs use calculated free testosterone, which depends on albumin assumptions that may not reflect your actual physiology (Vermeulen et al., 1999, Journal of Clinical Endocrinology and Metabolism). So the very metric the creator is optimizing toward is one that clinical labs frequently measure imprecisely. Any decision to change injection frequency should involve bloodwork interpreted by a licensed clinician, not a frequency experiment based on a subjective libido change.

Bottom line

This video gets the biology roughly right and avoids the most common TRT content pitfalls, no dose recommendations, no compound stacking, no miracle claims. The SHBG explanation is accurate in broad strokes. The problem is the leap from plausible mechanism to personal anecdote to general recommendation. Frequency optimization is real, but it is individual, it requires lab monitoring, and it does not work the same way for every man on TRT.