Peptide therapy claims from a nurse TikToker: what holds up?

What did @kristinastout actually say?

Christina, who identifies herself as a nurse practitioner, announced that her clinic now has access to Dihexa through a 503A compounding pharmacy. She described it as "a neurotropic peptide" that "helps to increase the growth of synapses in your brain," claiming benefits for "cognitive function, memory, brain fog" and neuroprotection. She also noted it requires cycling on and off, comes in oral pill form, and costs $250 for a 30-day supply through her clinic.

She did not mention any side effects, contraindications, or the fact that Dihexa has never been tested in a human clinical trial. That omission matters more than anything else in the video.

Does the science back this up?

Partially, in animals. The human evidence is essentially nonexistent, and that gap is enormous.

Dihexa (also known as N-hexanoic-Tyr-Ile-(6) aminohexanoic amide) was developed by researchers at Washington State University. The foundational animal study by McCoy et al. (2013, Journal of Pharmacology and Experimental Therapeutics) showed Dihexa outperformed angiotensin IV in improving spatial learning in scopolamine-impaired rats. The proposed mechanism involves the hepatocyte growth factor (HGF) and its receptor c-Met, which does play a role in synaptogenesis. So the synapse growth claim is not invented. It is derived from that preclinical work.

The problem is that rat cognition data does not translate cleanly to humans, and no Phase 1 safety trial, let alone an efficacy trial, has been published in humans. A compound with no published human pharmacokinetic data, no established safe dose range in people, and no regulatory review is being sold directly to consumers for $250 a month. That should give anyone pause.

What did they get wrong (or right)?

Credit where it is due: the synaptogenesis mechanism she describes is consistent with what the preclinical literature proposes. The cycling recommendation also reflects reasonable caution, though she gives no rationale for it and no evidence guides the cycling protocol in humans.

What she got wrong, or at minimum dangerously incomplete: she presented Dihexa as though its benefits for memory and brain fog in humans are established. They are not. Saying it "helps to increase the growth of synapses" and "can help with cognitive function" implies a level of clinical confidence the data does not support.

She also made no mention of potential risks. Dihexa is a potent HGF/c-Met agonist. Upregulating c-Met signaling has documented associations with tumor growth and oncogenesis (Organ and Bhatt, 2011, Nature Reviews Cancer). That is not a theoretical concern. It is a known pharmacological property of this pathway. Selling this compound without disclosing that risk in a public TikTok video, to an audience of people who may have no other medical guidance, is a real problem.

What should you actually know?

Dihexa is not FDA-approved for any indication. It is available through 503A compounding pharmacies, which are regulated by state boards of pharmacy and can compound for individual patients with a valid prescription. That does not mean the compound has been reviewed for safety or efficacy by the FDA.

The 503A framework exists for legitimate individualized compounding needs. It is not an approval pathway. A compound being available from a licensed compounding pharmacy is meaningfully different from a compound being proven safe and effective.

• No published human clinical trials exist for Dihexa as of mid-2025.
• The HGF/c-Met pathway it targets is implicated in cancer proliferation, a risk that was not mentioned in the video.
• Animal models showing cognitive benefit used impaired rats, not healthy adults seeking optimization.
• The $250 monthly cost is paid out of pocket, meaning insurance provides no oversight layer.

If you are considering Dihexa, the honest answer is that you would be an early adopter of a compound with promising but entirely preclinical data, real biological risks that are not disclosed in this video, and no established human dosing protocol. That may be a risk some people accept knowingly. But they deserve to make that choice with full information, not a TikTok pitch.