Semax vs Thymalin
Side-by-side comparison of key properties, dosing, and research.
- Summary
- Semax is a synthetic heptapeptide derived from ACTH developed in Russia. It is a potent nootropic that enhances memory, focus, and provides neuroprotection. Approved in Russia for cognitive disorders, stroke recovery, and traumatic brain injury.
- Thymalin is a polypeptide complex isolated from calf thymus glands (developed by the Russian Gerontology Institute), shown to restore immune function, extend lifespan, and reverse thymic involution. Clinical studies demonstrate improved immune parameters and up to 40% reduction in mortality in elderly patients.
- Half-Life
- Minutes (but effects persist for hours via BDNF induction)
- Not well characterized as a complex extract; individual peptides have varying kinetics
- Admin Route
- Intranasal, SubQ
- SubQ, IM
- Research
- —
- —
- Typical Dose
- 0.25–1 mg (250–1000 mcg)
- 10 mg IM or SC daily
- Frequency
- 1–2 times daily
- Once daily
- Key Benefits
- Enhances memory and learning
- Improves focus and concentration
- Increases mental energy and motivation
- Provides neuroprotection via BDNF and NGF upregulation
- Reduces cognitive decline
- May alleviate ADHD symptoms
- Supports recovery from brain injury and stroke
- Fast-acting — effects within 30–60 minutes
- Approved in Russia for cognitive disorders and stroke recovery
- Restores thymic function and T-cell immunity
- Extends healthy lifespan (documented in long-term studies)
- Reduces infectious disease incidence in elderly
- Normalizes immune parameters in immunodeficiency
- Anti-tumor immune surveillance
- Improves vaccine response in elderly
- Reduces cardiovascular mortality (40% in landmark Russian study)
- Normalizes neuroendocrine function
- Side Effects
- Headache (rare, often from higher doses)
- Anxiety or overstimulation at high doses
- Sleep disruption if dosed too late
- Irritability (uncommon)
- Very well tolerated in decades of Russian clinical use
- Mild injection site reactions
- Rare: mild allergic reaction (natural extract)
- Transient flu-like symptoms on initiation (immune activation)
- Stacks With
- —
- —