Comparison
Noopept vs Semax
Side-by-side of Noopept and Semax. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Noopept
Noopept cognitive enhancer profile: 10 to 30 mg dosage, dipeptide nootropic mechanism, memory effects, and how it compares to piracetam.
Semax
Semax peptide benefits: nootropic ACTH(4-10) analog without corticotropic activity. Cognitive enhancement, neuroprotection, intranasal dosing, Russian stroke.
Effects at a glance
Noopept
- •Russian dipeptide nootropic developed in the 1990s, registered in Russia 2002 for cognitive impairment
- •Roughly 1,000-fold higher per-mg potency than piracetam; therapeutic dose 10 to 30 mg/day
- •Active metabolite cycloprolylglycine modulates AMPA receptors and increases NGF and BDNF in rodent hippocampus
- •Russian RCTs in stroke recovery and vascular cognitive impairment show modest improvements over 4 to 8 weeks
- •Western evidence base is essentially absent; healthy-adult enhancement trials have not been published
- •Unscheduled in the US but not approved for human consumption; UK is prescription-only since 2014
Semax
- •Synthetic heptapeptide analog of ACTH(4-10) developed in Russia in the 1980s
- •Approved in Russia for ischemic stroke, cognitive impairment, and cerebrovascular disorders
- •Lacks the corticotropic activity of native ACTH due to the Pro-Gly-Pro stabilizing tail
- •Russian RCTs report improved cognitive recovery in acute ischemic stroke versus standard care
- •Modulates BDNF and NGF expression and dopaminergic signaling in preclinical models
- •Standard route is intranasal; not FDA approved; research-use-only outside Russia
Side-by-side
| Attribute | Noopept | Semax |
|---|---|---|
| Category | nootropic | peptide |
| Also known as | GVS-111, N-phenylacetyl-L-prolylglycine ethyl ester, Omberacetam | Met-Glu-His-Phe-Pro-Gly-Pro, ACTH(4-10) Pro-Gly-Pro analog |
| Half-life (hr) ↗ | 0.7 | 0.5 |
| Typical dose (mg) ↗ | 20 | 0.6 |
| Dosing frequency | 2 to 3 times daily, last dose before mid-afternoon | 2-3x daily (intranasal) |
| Routes | oral, sublingual | intranasal |
| Onset (hr) | 0.5 | 0.5 |
| Peak (hr) | 1 | 2 |
| Molecular weight | 318.37 | 813.94 |
| Molecular formula | C17H22N2O4 | C37H51N9O10S |
| Mechanism | Hydrolyzed to active metabolite cycloprolylglycine; AMPA receptor modulation, BDNF and NGF upregulation, antioxidant and antiexcitotoxic effects. | Modulates BDNF and NGF expression in hippocampus and cortex, enhances dopaminergic and serotonergic signaling, and reduces oxidative stress markers in preclinical ischemia models. Lacks corticotropic activity of native ACTH. |
| Legal status | Approved in Russia and CIS states; prescription-only in UK; unscheduled and unapproved in US, EU varies | Approved in Russia for stroke and cognitive disorders; not FDA approved; research-use-only grey market elsewhere |
| WADA status | unknown | unknown |
| DEA / Rx | Not scheduled in the US | Not FDA approved; not scheduled; research-chemical status outside Russia |
| Pregnancy | Not recommended | Not recommended; insufficient data |
| CAS | 157115-85-0 | 80714-61-0 |
| PubChem CID | 183503 | 9811102 |
| Wikidata | Q4321022 | Q4413083 |
Safety profile
Noopept
Common side effects
- headache
- irritability
- sleep disturbance with late-day dosing
- occasional blood pressure elevation
Contraindications
- pregnancy
- lactation
- pediatric use
- severe hepatic impairment
- severe renal impairment
Interactions
- memantine and other glutamatergic agents: theoretical AMPA-pathway interaction(minor)
- antidepressants: theoretical effect via BDNF axis, undocumented(minor)
- antihypertensives: occasional blood pressure elevation may require monitoring(minor)
Semax
Common side effects
- mild nasal irritation
- transient mild headache
- rare mild euphoria or activation
Contraindications
- pregnancy
- lactation
- acute psychotic disorder
- severe hypertension (caution due to mild activating effect)
Interactions
- stimulants (caffeine, amphetamines): potential additive activation; monitor for overstimulation(minor)
- antipsychotics: theoretical antagonism via dopaminergic modulation(minor)
Which Should You Take?
Noopept comes out ahead for most readers on the criteria we weight: 3 catalogued goals, controlled substance, oral dosing, with a Tier-B outcome catalogued. Semax is the right call when one of the conditionals below applies.
- → If your priority is memory, pick Noopept.
- → If your priority is stress and HPA-axis regulation, pick Noopept.
- → If your priority is long-term neuroprotection, pick Semax.
- → If your priority is stroke recovery, pick Semax.
Default choice: Noopept. Wider use case, and broader goal coverage. Reach for Semax only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Noopept and Semax?
Noopept and Semax differ in category (nootropic vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Noopept or Semax?
Noopept half-life is 0.7 hours; Semax half-life is 0.5 hours.
Can you stack Noopept with Semax?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper