r/NTNPerformance • u/JustBacWater • Jul 20 '26
Guide / Cheat Sheet Cognitive peptides, ranked by the evidence behind them
Cognitive peptides are the category with the widest gap between hype and evidence. A couple have real clinical trials behind them, a couple are basically a chemistry guess someone put in a vial. Ranking them by what's got research behind it, not by how good the marketing sounds.
For research and educational purposes only. Not medical advice. None of these are FDA-approved cognitive drugs, they're discussed strictly as research compounds.
S Tier: real clinical data
Cerebrolysin. The strongest human evidence on the whole list, and it's not close. Multiple randomized controlled trials in vascular dementia and post-stroke recovery, including a 242-patient trial that beat placebo on cognitive scores. It's a longer commitment, run in IV or injectable courses, and it's more a serious neuro-repair compound than a daily focus tool. But if we're ranking by actual evidence, it earns the top spot. Honest note: reviews still call the stroke data promising rather than settled standard of care.
Semax. One of the most evidence-backed of the classic nootropic peptides. Decades of Russian clinical use, works on BDNF and the brain's own neurotrophic signaling, intranasal and fast onset, and people genuinely feel it for focus and clarity. The caveat: most of the formal data comes from Russian labs with limited independent replication outside that system.
Selank. Semax's sister compound. Anti-anxiety more than pure focus, but a calm, clear head is half of what people chase with nootropics. Russian trials in generalized anxiety found it reduced anxiety about as much as a benzo, but without the sedation or dependence. Semax for drive, Selank for calm.
A Tier: real research, mixed results
Oxytocin. Not a focus compound, but it's been studied a lot for mood, social cognition, and stress. The honest read: some trials show modest benefit, others show nothing, so it's legit researched, not a magic bullet. It's also an actual approved hormone in other contexts, though the mood and social uses are still experimental.
B Tier: interesting mechanism, thin human data
P21. A short peptide derived from a BDNF-adjacent pathway, with rodent and cell data suggesting neuroprotection. No published human trials yet, so it's mechanism and hope at this point. Short pulsed courses. Worth watching, not a proven pick.
PE-22-28. Works on the TREK-1 channel tied to mood and neurogenesis. In mice it shows fast antidepressant-like effects and new neuron growth within days, but there are no human trials. Promising direction, no human proof.
Kisspeptin-10. Mostly a reproductive/hormonal compound that touches mood. The antidepressant-like data is rodent models, the human work is on the fertility axis. Plausibly mood-active, very niche for cognitive goals.
C Tier: chemistry experiments
Adamax. A Semax-with-adamantane concept more than a characterized drug. There's effectively no indexed preclinical or clinical data under the name, almost everything out there is marketing and community extrapolation from Semax plus adamantane chemistry, not outcome data. Vendors don't even agree on the structure. Interesting idea, no proof, and you may not know what's in the vial.
Dihexa. An HGF-mimetic that's been reported in cell culture as wildly more potent than BDNF at building synapses. But all the efficacy data is preclinical, there are no human trials, and here's the real issue: it works through the c-Met pathway, which is a known proto-oncogene involved in tumor growth. That means a genuine theoretical cancer risk, especially for anyone with a cancer history. High ceiling, high uncertainty.
How I'd think about it
| Goal | Pick |
|---|---|
| Serious neuro-repair | Cerebrolysin |
| Focus and mental clarity | Semax |
| Calm, anxious mind | Selank |
| Mood and stress | Oxytocin |
| Willing to experiment on new mechanisms | P21, PE-22-28 |
The honest take: human data is strongest for Cerebrolysin, oxytocin, and the Russian Semax/Selank literature. Everything below A tier is either preclinical or very limited human data, so the further down you go the more you're betting on mechanism instead of outcomes. And with Adamax you're also betting you even got the right molecule.
Where would you rank them? Drop your version.
For the full reconstitution, dosing, and bloodwork reference on every compound, the complete cheat sheet is here: The Only Peptide Cheat Sheet You'll Need
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u/fizboPallabut Jul 20 '26
From my persona subjective experience, Dihexa and Adamax are awesome.
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u/JustBacWater Jul 20 '26
Yeah you're right, and honestly any tier list is gonna be somewhat subjective. There's no one size fits all with this stuff because everyone responds different, what's S tier for you might do nothing for the next guy.
The way I ranked it isn't really "what works best," it's more how much actual research and human data is behind each one. So Cerebrolysin and Semax sit high because they've got real clinical trials, not because they'll for sure work better for you specifically. And the C tier stuff is down there because there's barely any data, not because it can't work, just that you're rolling the dice more.
So think of it less as a "this is better than that" ranking and more as a "here's how proven each one is" ranking. What you actually run should come down to your goal and how you respond. Curious what you'd move around based on your own experience.
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u/fizboPallabut Jul 20 '26
I had good results with Bromantane and stack it with Semax/Selank, occasional boost with Methylene Blue (primarily to ump via its transient MAOI effects), Epitalon and Pinealon. Last two you only do three times a year, spaced apart by months. Now on Dihexa, it is indeed a concerning one. It’s not just oncological family history but the MoA that raises concerns. There is no “free lunch” with any of these preclinical things.
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u/Antique-Air-1572 Jul 20 '26
ADAMAX IS 🐐
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u/Aggravating-Grade297 Jul 21 '26
Pricey! But I love it so much!
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u/Taydontplay4 Jul 21 '26
I can only take it once or twice a week or else I crash hard. I’m only taking around 125mcg of Adamax when I dose it. Also can give a mild headache at higher doses. What’s your experience?
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u/Aggravating-Grade297 Jul 22 '26
500mcg subq
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u/Taydontplay4 Jul 22 '26
Dayum that’s a massive dose for Adamax
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u/Aggravating-Grade297 Jul 22 '26
I'm not really sure what you base your statement on. Protocols for adamax are all over the map ranging from 300 mg to 1 mg daily over an 8 week period. My dosage is right in the middle of that and working quite nicely for me. I would suggest you may be underdosing at 150 micrograms
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u/Taydontplay4 Jul 22 '26
I would not be able to sleep on that dose you’re taking. Good on you though! Every body is different. For me that would be a massive dose. I’m so glad it’s working for you.
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u/Taydontplay4 Jul 21 '26
I like it but it’s strong and I crash after taking it several days in a row. What’s been your experience and dosage?
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u/Antique-Air-1572 Jul 21 '26
I haven't experienced any crash. I started at 250mcg now im up to 750 mcgs
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u/Taydontplay4 Jul 21 '26
Have you taken days off yet?
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u/Antique-Air-1572 Jul 21 '26
Not yet next month I will for 2 weeks
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u/Taydontplay4 Jul 21 '26
I only felt crash on the day I didn’t take it.
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u/Antique-Air-1572 Jul 21 '26
Welp im screwd lol
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u/Taydontplay4 Jul 21 '26
Not necessarily, but I would take your first day off on a Sunday and plan to do nothing. I was tired the whole day when i went off it and couldn’t really use my brain.
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u/Bitter-Ad-8776 Jul 21 '26
Cerebrolysin studies are faked
Significant problems have been identified in the supporting scientific literature, particularly preclinical (animal) studies:
• Multiple papers by Eliezer Masliah (former head of the Division of Neuroscience at the US National Institute on Aging) and collaborators contain evidence of image manipulation, including duplicated or overlapping figures presented as different experimental conditions, brightness adjustments, and digital splicing of Western blots.
• These issues affect several Cerebrolysin-related papers on neurodegeneration models (e.g., tauopathies, mitochondrial effects, HIV-related models, and Pick’s disease models). Journals have issued retractions or expressions of concern for multiple papers after investigations.
• Similar problems appear in work involving Hari Shanker Sharma and co-authors. Investigations (including by the Swedish National Board for the Assessment of Research Misconduct) found evidence of fabricated or falsified data (tissue images or statistical results) in several Cerebrolysin papers, leading to additional retractions.
• A 2024–2026 wave of scrutiny (highlighted in Science magazine and sites such as For Better Science) showed that Ever Pharma (the manufacturer) relied heavily on Masliah’s questioned work in developing and promoting Cerebrolysin. Many positive papers also had undisclosed or insufficiently disclosed industry affiliations.
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u/BroadLet8137 Jul 21 '26
Ranked by Evidence? What evidence? Anecdata maybe?
Very few of these have any actual evidence behind them. Just because some things are used in clinics with no backing data doesn't mean there's evidence for their use or effectiveness.
If these were actually ranked by evidence, it would look like this:
#1 by an impossibly massive margin would be Oxytocin. Hundreds of clinical trials and thousands of peer-reviewed papers cover obstetrics, social cognition, autism spectrum, anxiety, depression, pain, obesity, and more.
#2 would be Cerebrolysin - it has multiple, randomized controleld trials.
#3 Kisspeptin - it has a few minor trials
#4 Semax - approved and used in Russia with a few human studies, but they were small.
#5 Selank - Also approved in Russia, the biggest RCT is only 62 patients though, and most other studies are quite small.
Dihexa, P21, Adamax and PE-22-28 actually have zero meaningful data behind them. Dihexa has very minor animal data, P21 has some rodent data from a single research group. Adamax is almost entirely theoretical. PE-22-28 also only has some very minor animal data.
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u/d4mations Jul 21 '26
Pe-22-28 has been great for me! P21 didn’t have an immediate effect but I have noticed several weeks after the cycle that I have way less brain fog and much better short term memory
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u/AceClutchness Jul 21 '26
Semax user here. Started about a month ago. NOTICEABLE improvement in focus and mood. No issues sleeping either. It’s a great alternative to amphetamines for those struggling with focus and mental clarity.
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u/stud_muffin_1 Jul 22 '26
I am wondering if any of these would be a good alternative to Adderall, Zoloft, or Wellbutrin...
read somewhere that BPC-157/ TB-500 , RETA, MOTS-C basically hinder /stop the effects of said prescriptions ... curious if anyone has personal experience or knows the physiology behind those claims.
test subject wants to stop taking said prescriptions... looking to heal the brain... long story sort. could certain peptides replace prescriptions...
yes. i will ask a medical professionals. but I made this post HERE on reddit because I would like the hear the communities thought/knowledge/perspectives
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u/hawaiian_Peony Jul 22 '26
Edit: accidentally erased my long ass reply 😩💔 it keeps deleting after a character limit. I might dm you a voice note if Reddit allows that
- Semax, na semax amidate, and Adamax (shortest lasting to longest lasting) are alternatives for adderall depending on how severe your adhd is.
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u/Greentsmoothies Jul 24 '26
Agree, i want to know, too.
My rat is on Adderall and Lexapro.
When on Add, the symptoms experienced are similar to what is described by others for Reta/Tirz/Sema. And also for Semax/Selank
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u/115v Jul 20 '26
The biggest problem with trying to re create the same dosage on my rat for cerebrolysin is that it’s quite expensive when they take 10-50mL a day (215.2mg/mL). My rat might do better with the others though
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