Noopept (Omberacetam) vs Semax
Ultra-potent dipeptide nootropic and prodrug of cycloprolylglycine that enhances cognition through BDNF/NGF upregulation, AMPA receptor modulation, and multicomponent neuroprotection at doses 1000 times lower than piracetam
A brain-boosting peptide that supercharges your cognitive function by ramping up BDNF—the protein your neurons need to grow, connect, and stay sharp—all delivered through a simple nasal spray.
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
Noopept (Omberacetam)
10–10 mg
Semax
500–900 mcg/day
Frequency
Noopept (Omberacetam)
Multiple times daily
Semax
Once daily
Administration
Noopept (Omberacetam)
Oral (tablet/capsule)
Semax
Intranasal spray
Cycle length
Noopept (Omberacetam)
12+ weeks
Semax
4-6 weeks
Onset speed
Noopept (Omberacetam)
Rapid (hours to days)
Semax
Rapid (hours to days)
Evidence level
Noopept (Omberacetam)
Limited human trials
Semax
Moderate human trials (Phase 1-2)
Benefit ratings
Memory & Learning
Brain Protection
Mental Clarity
Cognitive Enhancement
Neuroprotection
Mental Energy
Compound specifications
Noopept (Omberacetam)
Molecular formula
C17H22N2O4
Molecular weight
318.4 g/mol
Half-life
Short plasma half-life (minutes); rapidly converted to active metabolite cycloprolylglycine which has a longer pharmacological duration; effects persist for hours after dosing
Bioavailability
Orally bioavailable with BBB penetration; metabolized to active cycloprolylglycine; approximately 1000-fold more potent than parent compound piracetam
CAS number
157115-85-0
Semax
Molecular formula
C37H51N9O10S
Molecular weight
813.9 g/mol
Half-life
Several minutes to hours (intranasal effects persist longer)
Bioavailability
High via intranasal route (directly reaches brain)
CAS number
80714-61-0
Dosing compared
Noopept (Omberacetam)
Oral
10 mg twice daily (20 mg/day)
Twice daily (morning and afternoon) · 56 days (8 weeks) per clinical study
Dose used in a controlled human study of mild cognitive impairment, improving cognition with good tolerability [6].
Semax
Intranasal
250-500 mcg/day
Once or twice daily · 1-2 weeks
Cognitive/nootropic practice with the 0.1% solution; downstream BDNF/NGF effects persist 12-24 h so dosing is once to twice daily [1][2].
500-900 mcg/day
Divided 2-3 times daily · 3-4 weeks
Mid-range nootropic practice dose; upregulates hippocampal BDNF/TrkB in animal models [1][2][3].
Best suited for
Noopept (Omberacetam)
Cognitive enhancement for learning, memory formation, and information retrieval
Noopept (Omberacetam) is particularly well-suited for individuals focused on cognitive enhancement for learning, memory formation, and information retrieval. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Neuroprotection against oxidative stress and age-related cognitive decline
Noopept (Omberacetam) is particularly well-suited for individuals focused on neuroprotection against oxidative stress and age-related cognitive decline. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Nootropic stacking — complements racetams, cholinergics, and neurotrophic peptides through distinct mechanisms
Noopept (Omberacetam) is particularly well-suited for individuals focused on nootropic stacking — complements racetams, cholinergics, and neurotrophic peptides through distinct mechanisms. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Support during periods of intense intellectual work or study
Noopept (Omberacetam) is particularly well-suited for individuals focused on support during periods of intense intellectual work or study. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Semax
Students and Knowledge Workers
If your day revolves around learning, studying, or processing complex information, Semax can be a game-changer. It enhances memory consolidation and recall while improving your ability to focus for extended periods—perfect for exam prep or demanding projects [6][12].
Those Seeking Mental Clarity
Brain fog? Semax works by boosting BDNF—the protein that helps neurons communicate effectively. [1][2] Users often report feeling like the 'mental static' clears away, leaving sharper, more efficient thinking in its place.
Neuroprotection Seekers
Beyond immediate cognitive benefits, Semax offers protective effects for your brain cells. [9] It acts as an antioxidant (especially against copper toxicity) [4][8] and supports neuronal health—valuable for anyone concerned about long-term brain wellness.
Recovery Support (Under Medical Supervision)
In Russia, Semax is approved for helping stroke patients and those with traumatic brain injuries recover cognitive function. [6] While not FDA-approved for this use elsewhere, the research shows meaningful neuroprotective and neurorestorative properties [7][9].
Side effects
Noopept (Omberacetam)
Common
- Headache
- Irritability or restlessness
- Sleep disturbance
- Mild gastrointestinal discomfort
- Vivid dreams
Uncommon
- Blood pressure increase
Serious
- Allergic reaction
Semax
Common
- Nasal irritation
- Mild headache
- Increased alertness
Uncommon
- Temporary blood pressure increase
- Dizziness
Serious
- Allergic reaction
Safety & evidence
Noopept (Omberacetam)
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
Noopept demonstrates excellent safety in Russian clinical trials with LD50 >2000 mg/kg (oral, rats)—approximately 100 times higher than therapeutic doses. No serious adverse events reported in human studies up to 30 mg/day for 6-12 weeks. Mild side effects (headache, irritability) occur in <5% of users and resolve with dose reduction. No carcinogenicity, mutagenicity, or teratogenicity in preclinical testing; minimal drug interactions due to lack of hepatic CYP450 metabolism.
Contraindications
- Known hypersensitivity to Noopept, piracetam, or other racetam-class compounds
- Pregnancy and breastfeeding — insufficient safety data
- Severe hepatic impairment — Noopept undergoes hepatic metabolism
- Severe renal impairment — metabolites are renally excreted
- Lactose intolerance (some tablet formulations contain lactose as excipient)
Semax
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
Semax has been used clinically in Russia for over 25 years with an excellent safety profile. [7][12] It's approved there for treating stroke, cognitive impairment, and optic nerve diseases. [6] Studies consistently show minimal side effects, mostly limited to mild nasal irritation when using the spray form. [6][9] Unlike stimulants, Semax doesn't appear to cause tolerance, dependence, or withdrawal symptoms even with extended use.
Contraindications
- Pregnancy or planning to become pregnant
- Currently breastfeeding
- History of seizures or epilepsy
- Known allergy to ACTH-related peptides
- Uncontrolled hypertension
Which is right for you?
Choose Noopept (Omberacetam) if...
- Cognitive enhancement for learning, memory formation, and information retrieval
- Neuroprotection against oxidative stress and age-related cognitive decline
- Nootropic stacking — complements racetams, cholinergics, and neurotrophic peptides through distinct mechanisms
- Support during periods of intense intellectual work or study
Choose Semax if...
- Cognitive enhancement
- Memory improvement
- Focus and concentration
- Neuroprotection