Noopept and Semax are both popular nootropics from the post-Soviet research tradition, but they differ in chemistry and how they're taken. Noopept is a small dipeptide that is reported to be orally active and is often grouped with racetams; Semax is a peptide given intranasally. Neither is FDA-approved.
At a glance
| Noopept | Semax | |
|---|---|---|
| Type | Dipeptide (racetam-like) | ACTH-fragment analog peptide |
| Typical route | Oral | Intranasal |
| Associated effects | Memory, learning (reported) | Focus, cognition, neuroprotection |
| Origin | Developed in Russia | Developed/used in Russia |
| FDA status | Not approved | Not approved |
| Western evidence | Limited | Limited |
The bottom line
Bottom line: The most practical difference is form: Noopept is reported to work orally, while Semax is delivered as a nasal spray. Both come from the same research tradition, both are described in terms of cognition and memory, and both lack large independent Western trials. Neither is FDA-approved.
Frequently asked questions
What's the difference between Noopept and Semax?
Noopept is a dipeptide reported to be orally active and is often grouped with racetams, while Semax is a peptide typically given as a nasal spray. Both are nootropics from the post-Soviet research tradition.
Is Noopept a peptide?
Noopept is a small dipeptide-derived compound, often discussed alongside racetam nootropics. Unlike many peptides, it is reported to be orally active.
Are they approved or proven?
Neither is FDA-approved, and large independent Western clinical trials are lacking for both. They are used as medicines or supplements of uncertain standing in some countries.
References
Combined peer-reviewed sources from both peptide guides. Inclusion is not endorsement.
- Ostroumova RU, Gudasheva TA, Zaplina AP, et al. Noopept stimulates the expression of NGF and BDNF in rat hippocampus. Bull Exp Biol Med. 2008. Peer-reviewed study
- Ostrovskaia RU, Vakhitova IuV, Salimgareeva MKh, et al. On the mechanism of noopept action: stress-induced kinases and neurotrophin expression. Eksp Klin Farmakol. 2010. Peer-reviewed study
- Pelsman A, Hoyo-Vadillo C, Gudasheva TA, et al. GVS-111 prevents oxidative damage and apoptosis in normal and Down's syndrome human cortical neurons. Int J Dev Neurosci. 2003. Peer-reviewed study
- Araj SK, Szeleszczuk Ł, Gubica T, et al. Physicochemical and structural analysis of N-phenylacetyl-L-prolylglycine ethyl ester (Noopept) - An active pharmaceutical ingredient with nootropic activity. J Pharm Biomed Anal. 2025. Peer-reviewed study
- Gürbüz P, Düzova H, Yildiz A, et al. Effects of noopept on cognitive functions and pubertal process in rats with diabetes. Life Sci. 2019. Peer-reviewed study
- Gurbuz P, Duzova H, Taslidere AC, et al. Effects of noopept on ocular, pancreatic and renal histopathology in streptozotocin induced prepubertal diabetic rats. Biotech Histochem. 2023. Peer-reviewed study
- Dolotov OV, Karpenko EA, Seredenina TS, et al. Semax, an analogue of ACTH(4-10), increases brain-derived neurotrophic factor protein in rat basal forebrain. J Neurochem. 2006. Peer-reviewed study
- Gusev EI, Skvortsova VI, Miasoedov NF, et al. Effectiveness of semax in the acute period of hemispheric ischemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 1997. Peer-reviewed study
- Gusev EI, Skvortsova VI, Chukanova EI. Semax in prevention of disease progression in patients with cerebrovascular insufficiency. Zh Nevrol Psikhiatr Im S S Korsakova. 2005. Peer-reviewed study
- Liu R, Chen Y, Huang H, et al. Semax peptide targets the μ opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice. Br J Pharmacol. 2025. Peer-reviewed study
- Sciacca MFM, Naletova I, Giuffrida ML, et al. Semax, a Synthetic Regulatory Peptide, Affects Copper-Induced Abeta Aggregation and Amyloid Formation in Artificial Membrane Models. ACS Chem Neurosci. 2022. Peer-reviewed study
- Glazova NY, Manchenko DM, Volodina MA, et al. Semax, synthetic ACTH(4-10) analogue, attenuates behavioural and neurochemical alterations following early-life fluvoxamine exposure in white rats. Neuropeptides. 2021. Peer-reviewed study