Semax side effects: what TikTok gets wrong about nasal irritation

What did @rivi.rl actually say?

The creator claims they have been taking semax and describe it as "insane" for their sales performance, specifically crediting it with improved objection handling. They also mention they "have not been able to eat" and respond to this by deciding to "triple" their MK-677 dose, apparently reasoning that MK-677's appetite-stimulating reputation would counteract the appetite suppression they are experiencing. The video is casual and anecdotal, framed as a relatable complaint, but the decisions described carry real risks worth examining.

To be clear: the creator is not presenting themselves as a medical professional. They are a salesperson sharing personal experience. That context matters. But 13,000 views means a lot of people are hearing this as informal guidance, which is exactly why it deserves scrutiny.

Does the science back this up?

Semax's cognitive effects have actual research behind them, which is more than most nootropics can say. The appetite-suppression concern, however, is real and underreported. Tripling any secretagogue dose based on a self-diagnosed nutritional deficit is not a strategy supported by evidence.

Semax is a synthetic heptapeptide derived from ACTH(4-7). Russian research, including work by Bobyntsev et al. (2015, Bulletin of Experimental Biology and Medicine), has documented effects on BDNF expression and dopaminergic activity in animal models. Human data is thin but not nonexistent. Semax has been studied clinically in Russia for stroke recovery and attention tasks. The cognitive-performance angle is plausible, not proven in healthy adults doing sales calls.

MK-677 (ibutamoren) is a growth hormone secretagogue, not a peptide. It works by mimicking ghrelin and stimulating GH and IGF-1 release. Ghrelin is an appetite hormone, so MK-677 does typically increase appetite. But tripling a dose to overcome appetite suppression from a different compound is not how pharmacology works, and no published study supports that approach.

What did they get wrong (or right)?

Credit where it is due: semax's association with dopaminergic signaling and attention is genuinely supported in animal and some human literature. If the creator is noticing improved focus or verbal fluency, that is not implausible given semax's mechanism. They are not making something up from whole cloth.

What they got wrong is the improvised dose escalation. "I decided to triple my MK-dose" is the kind of sentence that should come with a lot more context than a TikTok caption. MK-677 at standard doses already raises concerns about water retention, insulin resistance, and elevated fasting glucose. Kanaley et al. (2008, Journal of Clinical Endocrinology and Metabolism) noted glucose metabolism effects at therapeutic GH secretagogue doses. Tripling a dose compounds those risks without any corresponding evidence of benefit.

The appetite suppression side effect from semax is also worth naming directly. It is a known phenomenon and not discussed enough in biohacking communities. Ignoring it and overriding it with another compound is not a solution.

What should you actually know?

If you are using semax and losing your appetite, that is a signal worth paying attention to, not routing around with a higher dose of a different drug. Appetite suppression from peptides or nootropics can reflect real physiological stress, not just an inconvenience.

MK-677 is frequently discussed as if it is benign because it is not an injectable peptide and is sold as a research chemical. It is not benign. Long-term GH secretagogue use in healthy adults has not been adequately studied for safety. The compound has shown promise in specific clinical contexts, including muscle wasting in older adults (Chapman et al., 1996, Journal of Clinical Endocrinology and Metabolism), but those populations and doses are not the same as a healthy adult self-dosing for performance.

Semax remains unapproved by the FDA for any indication. It is legal to purchase as a research chemical in the US but is not approved for human use outside Russia and Ukraine. Anyone stacking it with MK-677 and adjusting doses based on how their sales calls are going is operating well outside any framework of clinical oversight.

The bottom line

The cognitive benefits the creator describes for semax are biologically plausible, but the evidence in healthy adults doing cognitively demanding work is weak. The decision to triple MK-677 in response to appetite suppression is the part that genuinely concerns us. That is not a strategy, it is improvisation with compounds that affect GH axis regulation and glucose metabolism. If you are experiencing significant appetite changes on any peptide regimen, that is a conversation for a clinician, not a dose adjustment you make on your own.