Noopept vs Semax

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

Noopept

Noopept (N-phenylacetyl-L-prolylglycine ethyl ester) is a peptide-derived nootropic developed in Russia. While technically a dipeptide prodrug rather than a true peptide, it's often discussed alongside peptide nootropics.

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Semax

Semax is a synthetic peptide derived from ACTH (adrenocorticotropic hormone). Developed in Russia as a nootropic and neuroprotective agent.

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Side-by-Side Comparison

Aspect	Noopept	Semax
Dose Range	10 mg–30 mg	300 mcg–600 mcg
Frequency	2x daily	2x daily
Cycle Length	4–6 weeks	2–4 weeks
Route	oral	intranasal
Mechanism	Metabolized to cycloprolylglycine which modulates AMPA and NMDA receptors, increases NGF and BDNF expression, and provides neuroprotective effects through antioxidant mechanisms.	Enhances BDNF expression, modulates dopamine and serotonin systems, and provides neuroprotective effects. Increases attention, memory formation, and learning.
Typical Dosage	Oral: 10-30mg daily, typically divided into 2-3 doses. Sublingual use may enhance absorption. Some users go higher but effects may plateau.	Intranasal: 200-600mcg 2-3 times daily. Higher doses (up to 1mg) used in clinical settings for stroke recovery.
Administration	Oral or sublingual administration. Unlike most peptides, it's orally bioavailable. Can be taken with or without food.	Primarily administered intranasally. N-Acetyl Semax Amidate (NASA) is a modified version with enhanced stability and potency.
Side Effects	Headache (often from choline depletion), irritability, insomnia if taken late, and occasional brain fog during initial use.	Generally well-tolerated. May cause mild irritability or hair shedding in some users.
Best For	Cognitive Performance	Cognitive Performance