@gabi.brandao's testosterone frequency claims, fact-checked

What did @gabi.brandao actually say?

Straightforwardly: we cannot tell. The transcript available for this video is garbled beyond comprehension. What appears in the caption, "why an injection every 15 to 20 days is the worst thing you can do," is the actual claim being made. The transcript itself is a machine-translation disaster that references interviews, resumes, and 19th-century Europe, none of which have anything to do with testosterone replacement therapy. We are working from the caption claim, the hashtags, and the standard argument that circulates in Brazilian bodybuilding communities about injection frequency. That argument is well-known: long injection intervals with testosterone cause peaks and troughs that produce symptoms. The caption frames this as settled fact. It is not quite that simple, but it is not entirely wrong either. We will treat the claim at face value, because the caption makes the core assertion plainly enough.

Does the science back this up?

Partly, yes. Injection interval genuinely matters for hormone stability, but "worst thing you can do" is hyperbole that ignores clinical context. Testosterone enanthate and cypionate have half-lives of roughly 7 to 8 days, which means a 15 to 20-day injection interval does produce a significant trough by the time the next dose arrives. Testosterone levels can fall below physiological range in many patients before day 15, which produces the classic "roller coaster" symptom pattern: energy, libido, and mood improve post-injection, then decline sharply before the next dose. Rastrelli et al. (2018, Andrology) documented that symptom variability between injections is a real clinical problem tied directly to pharmacokinetic fluctuation. A systematic review by Bhasin et al. (2010, Journal of Clinical Endocrinology and Metabolism) established that weekly or twice-weekly injections of shorter-acting esters maintain more stable serum levels than biweekly or monthly regimens. However, some patients do maintain adequate trough levels beyond 14 days, depending on their metabolism, dose, and ester used. Blanket statements about every patient are always going to miss someone.

What did they get wrong (or right)?

The underlying pharmacology is right. Injecting testosterone enanthate or cypionate every 15 to 20 days is generally poor practice for symptom management in TRT. That part checks out. Where the claim oversimplifies is in framing a 15 to 20-day interval as universally catastrophic. Long-acting injectable testosterone undecanoate, marketed as Nebido or Aveed, is specifically designed for 10 to 14-week intervals and is approved by regulatory agencies in multiple countries for hypogonadism. Rohayem et al. (2017, Andrologia) showed that testosterone undecanoate produces acceptable stability in many patients at those intervals. So the claim, applied without specifying which ester is being discussed, is misleading. For cypionate or enanthate, the argument is solid. Stated as a universal rule for all injectable testosterone, it is inaccurate. The bodybuilding community often conflates ester types when making sweeping injection frequency recommendations, and this appears to be an example of that pattern.

What should you actually know?

Injection frequency should be matched to the specific ester's half-life and your individual pharmacokinetics, confirmed through bloodwork, not a social media rule of thumb. For testosterone enanthate and cypionate, most clinical guidelines and endocrinologists now recommend weekly or twice-weekly injections to maintain stable serum levels. The Endocrine Society's 2018 clinical practice guidelines on male hypogonadism support frequent dosing schedules for short-to-medium-acting esters specifically to minimize peak-to-trough variability. If you are on a 15 to 20-day injection schedule and feeling symptomatic in the days before your next injection, that symptom pattern is real and worth discussing with a prescribing clinician. Adjusting frequency is a clinical decision that requires monitoring serum testosterone, hematocrit, and other labs. Nobody on Instagram, including this creator, should be setting your injection schedule. A regulated telehealth provider can order labs, review your pharmacokinetics, and adjust your protocol based on data rather than a video caption.