Nootropic · 5mg × 10 vials
In plain terms: Adamax (Dihexa) is a research compound — oral, fast-acting and well studied.
Dihexa (N-hexanoic-Tyr-Ile-(6) aminohexanoic amide, also called PNB-0408) is a small, orally-bioavailable, blood-brain-barrier-penetrant analog of angiotensin IV developed in the lab of Joseph Harding and John McCoy at Washington State University in the early 2010s. The parent compound, angiotensin IV, was already known to have memory-enhancing effects in animal models but was peptidase-sensitive and poorly bioavailable. The Harding/McCoy team engineered Dihexa by attaching a hexanoic acid cap on the N-terminus and a 6-aminohexanoic acid amide on the C-terminus, which makes it stable to peptidase degradation and small enough to cross the BBB after oral dosing. Mechanistically, Dihexa is best characterized as a hepatocyte growth factor (HGF) potentiator, it binds HGF directly and stabilizes the HGF-c-Met receptor interaction, amplifying signaling through the c-Met tyrosine kinase pathway. The downstream consequence in the CNS, per the WSU rat work, is rapid induction of dendritic arborization and synaptogenesis (spinogenesis) in the hippocampus, with picomolar potency in dissociated hippocampal neuron cultures and reversal of scopolamine-induced memory deficits at oral doses ~10 million-fold lower than the parent angiotensin IV. The community summary, oversimplified but directionally correct, is that Dihexa drives new synapse formation, which is why the marketing line "10x more potent than BDNF" attached to it, that figure originates in the Harding lab's spinogenesis assays comparing molar potency of Dihexa to BDNF in dendritic spine formation, not in any direct head-to-head functional comparison.
The same c-Met activation that drives spinogenesis is also a well-characterized oncogenic pathway, c-Met is dysregulated or overexpressed in a long list of solid tumors (lung, gastric, hepatocellular, renal, glioblastoma) and HGF/c-Met is an active target of anti-cancer drug development. There is no human data showing Dihexa causes or accelerates cancer, but the theoretical mechanism is the central caveat that every cautious physician commentator raises, and is the reason the community-standard protocol is pulsed (4-8 weeks on, then off) rather than continuous.
Typical dose ranges by experience level — educational reference. Message us and we tailor it to you.
Beginner band sits at the conservative end of the 5-45 mg/day community range. The reason to start low is that there is no human dose-response curve in published literature, all dosing is preclinical mouse-extrapolated plus community self-experiment, so cautious titration is the only defensible approach. Subjective effects most often described as "verbal fluency improvement", "easier word recall", "thoughts connect faster". Effects build over 1-2 weeks of daily dosing.
Intermediate band is where most experienced community users sit. r/Nootropics and r/Peptides protocol writeups cluster heavily around 12-25 mg/day for the 4-8 week pulse. Splitting AM/midday is reported to give more even daytime cognitive coverage than single morning dosing. Above 25 mg/day there are diminishing returns in self-reports and the cancer-risk caveat scales with cumulative exposure, so the intermediate ceiling is also a practical risk ceiling for most users.
Above 45 mg/day there is no reported additional benefit and the theoretical risk increases. Advanced use is more about pulse timing (around exam windows, project sprints, or post-injury cognitive recovery research contexts) than chronic dose escalation. Stacking with Semax/Selank is more common at the intermediate-to-advanced bands than dose-pushing solo Dihexa.
Straight talk — what people actually report, and what the studies measured.
Peer-reviewed studies and clinical guidelines — tap any to read the source.
original WSU pharmacology, oral activity, scopolamine reversal in rats
Read study ↗PubMedBenoist CC, Wright JW, Zhu M, et al. Facilitation of hippocampal synaptogenesis and spatial memory by C-terminal truncated Nle1-angiotensin IV analogs. J Pharmacol Exp Ther 2011synaptogenesis mechanism, hippocampal spine formation
Read study ↗PubMedWright JW, Harding JW. The brain hepatocyte growth factor/c-Met receptor system: a new target for the treatment of Alzheimer's disease. J Alzheimers Dis 2015HGF/c-Met framing for AD therapeutics, includes Dihexa
Read study ↗PubMedWright JW, Harding JW. Importance of the brain angiotensin system in Parkinson's disease. Parkinsons Dis 2012angiotensin IV system in neurodegenerative disease
Read study ↗PubMedBenoist CC, Kawas LH, Zhu M, et al. The procognitive and synaptogenic effects of angiotensin IV-derived peptides are dependent on activation of the hepatocyte growth factor/c-met system. J Pharmacol Exp Ther 2014c-Met dependence of synaptogenesis effect
Read study ↗PubMedKawas LH, McCoy AT, Yamamoto BJ, et al. Development of angiotensin IV analogs as hepatocyte growth factor/Met modifiers. J Pharmacol Exp Ther 2012HGF binding and stabilization mechanism
Read study ↗Aggregated sentiment from public forums & socials — real-world reports, not individual endorsements.
Subjective cognitive lift: most reliably reported effect, described as "easier word recall", "verbal fluency improvement", "thoughts connect faster", "feels like the cognitive room got bigger". Onset within 1-2 weeks of daily dosing.
Headache: occasional, mild, usually first week. Reported by a minority on r/Nootropics, typically resolves.
Sleep disturbance / vivid dreams: minority of users report increased dream vividness or lighter sleep during the pulse window. Switching to morning-only dosing usually resolves.
Mild irritability or "wired" feeling at higher doses (>25 mg/day): occasional, addressable with dose reduction.
"Brain fog" rebound after cycling off: minority report a subjective dip in cognition for 1-2 weeks after stopping a pulse, then return to baseline. Not documented in literature.
The "10x BDNF" marketing line: pervasive in community discussion, originates from molar-potency comparisons in spinogenesis assays in the Harding lab papers, often misrepresented as a head-to-head functional comparison. Users who took it at face value sometimes report disappointment that the subjective effect is "noticeable but not magical", users who came…
Route: oral (community standard), sublingual (faster onset, similar AUC), topical/transdermal (less common, used in some early protocols with PLO or DMSO carrier)
Injection site: N/A
Storage: refrigerated, ~30 days after reconstitution. Lyophilized vials room-temp short-term, refrigerated for long-term storage.
Notes: Oral bioavailability is the headline feature of Dihexa, the WSU work specifically engineered the molecule for it. Most community users take it dissolved in a small amount of liquid (water, MCT oil, or BAC) and either swallow or hold under the tongue for 30-60 sec before swallowing. Sublingual is reported by users to feel slightly faster-onset but the total daily AUC is similar. Topical with DMSO is documented in older nootropic forum protocols but is the least common route today. Take with or without food, no clinical fasting requirement. Cycle 4-8 weeks on, then at least 4 weeks off, do not run continuously.