Peptides for depression and anxiety: what the science says

What did @daviddemesquita actually say?

The creator's core claim is that semax and selank should not be taken together, not because they're dangerous in combination, but because they serve opposite purposes and are better used situationally. He says semax "drives up dopamine levels" and BDNF to support mood and motivation, while selank calms anxiety through GABA pathways, similar in spirit to gabapentin. He warns that most TikTok peptide content is just ChatGPT output read aloud by people who don't understand the pharmacology.

To his credit, he's not saying this is a dangerous combination. His actual position is more nuanced: these peptides work better when deployed strategically rather than stacked together every day. That's a reasonable therapeutic philosophy, even if some of his mechanistic explanations don't fully hold up under scrutiny.

Does the science back this up?

Partly, but with important caveats. Semax is a synthetic heptapeptide derived from ACTH, studied primarily in Russian research. It does appear to influence BDNF expression, which is the "BDF" the creator likely meant. Dolotov et al. (2006, Journal of Molecular Neuroscience) found semax increased BDNF mRNA in rat brain tissue. Dopamine modulation is less direct and more speculative in the human literature.

Selank is a synthetic analog of tuftsin, and Russian clinical work, including Zozulya et al. (2001, Bulletin of Experimental Biology and Medicine), suggests it has anxiolytic effects and may interact with the GABAergic system. However, calling it a straightforward GABA-booster the way gabapentin works is an oversimplification. Gabapentin binds to voltage-gated calcium channels, not GABA receptors directly, and selank's mechanism is not equivalent. The comparison is illustrative but imprecise.

No peer-reviewed human trials exist on co-administration of semax and selank. This is a significant gap. The creator is offering a theoretical rationale, not evidence-based guidance.

What did they get wrong (or right)?

The creator gets credit for pushing back on the "just mix everything" culture on TikTok. The instinct that combining a stimulating peptide with a calming one might blunt the effect of both is pharmacologically reasonable, even if the supporting evidence is thin.

Where he goes wrong: the gabapentin comparison is misleading. He frames selank and gabapentin as working through shared GABA mechanisms, implying similar effects. Gabapentin's primary action is on alpha-2-delta subunits of calcium channels, not direct GABA receptor agonism. Selank's proposed anxiolytic mechanism involves enkephalin degradation inhibition and possible serotonin modulation, not just GABA. Collapsing these into the same category misrepresents both compounds.

The dopamine claim for semax is also presented with more certainty than the evidence warrants. Most semax research is preclinical or from small Russian trials. Saying it "drives up dopamine" as a confident mechanism overstates what's established in the literature for humans.

• Right: situational use over daily stacking is a defensible approach
• Right: BDNF connection to semax has some research support
• Wrong: the gabapentin-selank equivalence is an oversimplification
• Wrong: dopamine mechanism stated with more confidence than evidence allows
• Unverifiable: the "you don't want balance" framing has no clinical basis

What should you actually know?

Both semax and selank are research peptides. Neither has FDA approval for any indication. The overwhelming majority of data on these compounds comes from Soviet-era and Russian Federation research, which, while not worthless, has not been replicated in large Western randomized controlled trials. Anyone presenting confident mechanistic claims about these peptides for human neurochemistry is working well ahead of the available evidence.

The creator's practical advice, using an activating peptide in the morning and a calming one in the evening as needed, is not harmful framing. But it should be understood as a clinical hypothesis, not established protocol. If you're considering either peptide, that conversation belongs with a licensed provider who can assess your full health picture, not a TikTok comment thread or a ChatGPT session.

The irony is that the creator criticizes others for copying ChatGPT while himself presenting mechanistic claims that lack rigorous human trial support. That doesn't make him wrong about everything, but it's worth noting.