Comparison
NMN vs Semax
Side-by-side of NMN 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.
NMN
NMN supplements are oral nicotinamide mononucleotide capsules sold for longevity, energy, and metabolic health. They raise plasma NAD+ 30-90% at 250-1000.
Semax
Semax peptide benefits: nootropic ACTH(4-10) analog without corticotropic activity. Cognitive enhancement, neuroprotection, intranasal dosing, Russian stroke.
Effects at a glance
NMN
- •Plasma NAD+ rises 30-90% at 250-1000 mg/day across human PK studies
- •Tissue NAD+ rise is inconsistent across human trials (Yoshino 2021, Igarashi 2022)
- •No human trials measure hard endpoints (mortality, CV events, cancer); evidence is biomarker-only
- •Most trials cluster at 250-500 mg/day; dose-response above 250 mg/day is poorly characterized
- •FDA position contested; widely sold as supplement but with regulatory uncertainty
- •Marketing claims for fertility and longevity outrun the human trial evidence substantially
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 | NMN | Semax |
|---|---|---|
| Category | supplement | peptide |
| Also known as | nicotinamide mononucleotide, beta-NMN | Met-Glu-His-Phe-Pro-Gly-Pro, ACTH(4-10) Pro-Gly-Pro analog |
| Half-life (hr) ↗ | 4 | 0.5 |
| Typical dose (mg) ↗ | 250 | 0.6 |
| Dosing frequency | 1x daily, often morning | 2-3x daily (intranasal) |
| Routes | oral, sublingual | intranasal |
| Onset (hr) | 1 | 0.5 |
| Peak (hr) | 3 | 2 |
| Molecular weight | 334.22 | 813.94 |
| Molecular formula | C11H15N2O8P | C37H51N9O10S |
| Mechanism | Direct precursor in the NAD+ salvage pathway; converted to NAD+ by NMNAT enzymes in essentially every tissue. Raised NAD+ supports sirtuin and PARP enzyme activity. | 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 | Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia | Approved in Russia for stroke and cognitive disorders; not FDA approved; research-use-only grey market elsewhere |
| WADA status | allowed | unknown |
| DEA / Rx | Not scheduled | Not FDA approved; not scheduled; research-chemical status outside Russia |
| Pregnancy | Insufficient data; precautionary avoidance | Not recommended; insufficient data |
| CAS | 1094-61-7 | 80714-61-0 |
| PubChem CID | 14180 | 9811102 |
| Wikidata | Q418972 | Q4413083 |
Safety profile
NMN
Common side effects
- mild GI upset (rare)
- occasional headache
- flushing (rare)
Contraindications
- pregnancy and lactation (precautionary, no data)
- active cancer (theoretical concern, not evidence-based)
Interactions
- metformin: no clinically significant interaction documented; both modulate metabolism through different mechanisms(minor)
- chemotherapy agents: theoretical concern about supporting cancer cell proliferation; coordinate with oncology team(moderate)
- CD38 inhibitors: would amplify NMN-induced NAD+ rise; not clinically relevant for most users(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?
NMN comes out ahead for most readers on the criteria we weight: 3 catalogued goals, Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia, oral dosing, with a Tier-A outcome catalogued. Semax is the right call when one of the conditionals below applies.
- → If your priority is healthspan extension, pick NMN.
- → If your priority is energy and stamina, pick NMN.
- → If your priority is focus or working memory, pick Semax.
- → If your priority is long-term neuroprotection, pick Semax.
Edge case: Half-lives differ materially (NMN ~4 hr vs Semax ~0.5 hr). NMN reaches steady state faster; Semax is easier to dial in if tolerability is uncertain.
Default choice: NMN. Wider use case, a Tier-A evidence outcome catalogued, 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 NMN and Semax?
NMN and Semax differ in category (supplement vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, NMN or Semax?
NMN half-life is 4 hours; Semax half-life is 0.5 hours.
Can you stack NMN 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