Comparison
N-Acetyl Cysteine vs Selank
Side-by-side of N-Acetyl Cysteine and Selank. 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.
N-Acetyl Cysteine
NAC supplement benefits cover glutathione synthesis, liver and antioxidant support, and hangover recovery. Evidence strongest at 1200-2400 mg/day.
Selank
Selank peptide benefits: tuftsin analog heptapeptide, intranasal anxiolytic and nootropic. Russian clinical data, dosing, half-life, safety.
Effects at a glance
N-Acetyl Cysteine
- •Replenishes intracellular glutathione by supplying cysteine, the rate-limiting amino acid for synthesis
- •First-line antidote for acetaminophen toxicity, restoring hepatic glutathione before fulminant injury occurs
- •Reduces sputum viscosity in chronic bronchitis and COPD at 600 to 1200 mg/day over months
- •Modest symptom reductions in OCD and trichotillomania at 1200 to 2400 mg/day across small RCTs
- •Mixed evidence for psychiatric adjunct use in bipolar depression and schizophrenia negative symptoms
- •Inhaled forms can trigger bronchospasm in active asthma; oral use is the standard biohacker route
Selank
- •Synthetic heptapeptide analog of tuftsin developed in Russia in the 1990s
- •Approved in Russia for generalized anxiety disorder and asthenic conditions
- •Russian RCTs report anxiolytic effects comparable to medazepam without sedation or dependence
- •Modulates GABAergic and serotonergic signaling and BDNF expression in preclinical models
- •Most commonly administered intranasally; subcutaneous use is anecdotal
- •No Western-validated trials; not FDA approved; research-use-only outside Russia
Side-by-side
| Attribute | N-Acetyl Cysteine | Selank |
|---|---|---|
| Category | supplement | peptide |
| Also known as | NAC | TP-7, Tuftsin analog |
| Half-life (hr) ↗ | 5.6 | 0.5 |
| Typical dose (mg) ↗ | 1200 | 0.4 |
| Dosing frequency | 1 to 3 times daily, split dosing preferred | 2-3x daily (intranasal) |
| Routes | oral, iv | intranasal, subcutaneous |
| Onset (hr) | 1 | 0.25 |
| Peak (hr) | 2 | 1 |
| Molecular weight | 163.19 | 751.85 |
| Molecular formula | C5H9NO3S | C33H57N11O9 |
| Mechanism | Deacetylated to cysteine, the rate-limiting precursor for glutathione synthesis; also directly scavenges reactive oxygen species and modulates glutamate signaling. | Modulates GABAergic, serotonergic, and dopaminergic signaling. Increases BDNF expression in hippocampal neurons in preclinical models. Modulates enkephalin levels and immune cytokine signaling via tuftsin-like activity. |
| Legal status | OTC in most jurisdictions; restricted periods in US history (FDA reclassified 2022) | Approved as a prescription anxiolytic in Russia; not FDA approved; research-use-only grey market in most other jurisdictions |
| WADA status | allowed | unknown |
| DEA / Rx | OTC supplement (US, post-2022); Rx indications also exist (acetaminophen overdose, mucolytic) | Not FDA approved; not scheduled; research-chemical status outside Russia |
| Pregnancy | Used clinically in pregnancy for specific indications; consult clinician | Not recommended; insufficient data |
| CAS | 616-91-1 | 129954-34-3 |
| PubChem CID | 12035 | 11765600 |
| Wikidata | Q413299 | Q4416793 |
Safety profile
N-Acetyl Cysteine
Common side effects
- sulfur-like taste or odor
- nausea
- flatulence
- diarrhea
Contraindications
- active asthma attack (inhaled form can trigger bronchospasm)
- known NAC hypersensitivity
Interactions
- nitroglycerin: potentiates vasodilation, risk of hypotension and headache(moderate)
- activated charcoal: reduces NAC absorption when used for acetaminophen overdose(moderate)
- anticoagulants: theoretical additive antiplatelet effect at high doses(minor)
Selank
Common side effects
- mild nasal irritation (intranasal)
- transient drowsiness (uncommon)
- mild headache
Contraindications
- pregnancy
- lactation
- severe psychiatric disorder (insufficient data)
Interactions
- benzodiazepines: additive anxiolytic effect; potential for over-sedation when stacked(moderate)
- SSRIs: no documented adverse interaction; co-administration described in Russian protocols(minor)
Which Should You Take?
N-Acetyl Cysteine comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC, oral dosing, with a Tier-A outcome catalogued. Selank is the right call when one of the conditionals below applies.
- → If your priority is healthspan extension, pick N-Acetyl Cysteine.
- → If your priority is post-training recovery, pick N-Acetyl Cysteine.
- → If your priority is focus or working memory, pick Selank.
- → If your priority is anxiety reduction, pick Selank.
Edge case: If you want to avoid research-only / gray-market sourcing, N-Acetyl Cysteine is the more accessible choice.
Default choice: N-Acetyl Cysteine. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Selank 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 N-Acetyl Cysteine and Selank?
N-Acetyl Cysteine and Selank 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, N-Acetyl Cysteine or Selank?
N-Acetyl Cysteine half-life is 5.6 hours; Selank half-life is 0.5 hours.
Can you stack N-Acetyl Cysteine with Selank?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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