Comparison
N-Acetyl Cysteine vs Noopept
Side-by-side of N-Acetyl Cysteine and Noopept. 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.
Noopept
Noopept cognitive enhancer profile: 10 to 30 mg dosage, dipeptide nootropic mechanism, memory effects, and how it compares to piracetam.
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
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
Side-by-side
| Attribute | N-Acetyl Cysteine | Noopept |
|---|---|---|
| Category | supplement | nootropic |
| Also known as | NAC | GVS-111, N-phenylacetyl-L-prolylglycine ethyl ester, Omberacetam |
| Half-life (hr) ↗ | 5.6 | 0.7 |
| Typical dose (mg) ↗ | 1200 | 20 |
| Dosing frequency | 1 to 3 times daily, split dosing preferred | 2 to 3 times daily, last dose before mid-afternoon |
| Routes | oral, iv | oral, sublingual |
| Onset (hr) | 1 | 0.5 |
| Peak (hr) | 2 | 1 |
| Molecular weight | 163.19 | 318.37 |
| Molecular formula | C5H9NO3S | C17H22N2O4 |
| Mechanism | Deacetylated to cysteine, the rate-limiting precursor for glutathione synthesis; also directly scavenges reactive oxygen species and modulates glutamate signaling. | Hydrolyzed to active metabolite cycloprolylglycine; AMPA receptor modulation, BDNF and NGF upregulation, antioxidant and antiexcitotoxic effects. |
| Legal status | OTC in most jurisdictions; restricted periods in US history (FDA reclassified 2022) | Approved in Russia and CIS states; prescription-only in UK; unscheduled and unapproved in US, EU varies |
| WADA status | allowed | unknown |
| DEA / Rx | OTC supplement (US, post-2022); Rx indications also exist (acetaminophen overdose, mucolytic) | Not scheduled in the US |
| Pregnancy | Used clinically in pregnancy for specific indications; consult clinician | Not recommended |
| CAS | 616-91-1 | 157115-85-0 |
| PubChem CID | 12035 | 183503 |
| Wikidata | Q413299 | Q4321022 |
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)
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)
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. Noopept 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 Noopept.
- → If your priority is memory, pick Noopept.
Edge case: If you want to avoid controlled substance, 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 Noopept 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 Noopept?
N-Acetyl Cysteine and Noopept differ in category (supplement vs nootropic), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, N-Acetyl Cysteine or Noopept?
N-Acetyl Cysteine half-life is 5.6 hours; Noopept half-life is 0.7 hours.
Can you stack N-Acetyl Cysteine with Noopept?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper