Testagen vs Dihexa
Side-by-side comparison of key properties, dosing, and research.
- Summary
- Testagen is a tetrapeptide bioregulator (Lys-Glu-Asp-Gly) developed by Professor Vladimir Khavinson, tissue-specific for the testes. It supports Leydig cell function, normalization of testosterone biosynthesis, and spermatogenic activity. Testagen is used in men's health protocols for age-related testosterone decline, male fertility support, and testicular anti-aging.
- Dihexa is a potent experimental oligopeptide derived from angiotensin IV that dramatically enhances synaptogenesis. Preclinical research shows cognitive enhancement orders of magnitude more potent than BDNF — it is considered one of the most powerful nootropic compounds in research, but has very limited human safety data.
- Half-Life
- Short (minutes); sustained gene-regulatory effects
- Unknown (limited pharmacokinetic data)
- Admin Route
- SubQ, Oral
- Oral, SubQ, Topical
- Research
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- Typical Dose
- 10 mg per day
- 5–10 mg
- Frequency
- Daily for 10–30 days
- Daily
- Key Benefits
- Supports endogenous testosterone synthesis via Leydig cell normalization
- Promotes spermatogenesis and sperm quality
- Anti-aging effects on testicular tissue
- May attenuate age-related testosterone decline
- Mechanistically distinct from TRT — does not suppress HPG axis
- Useful adjunct to Gonadorelin and Kisspeptin-10 in male hormonal protocols
- Supports male fertility without exogenous hormone replacement
- Dramatically increases synapse formation (potentially 10 million× more potent than BDNF in animal models)
- Enhances memory and learning
- May reverse cognitive decline
- Improves neuroplasticity and executive function
- Long-lasting cognitive benefits from short courses
- Potential therapeutic agent for Alzheimer's
- Side Effects
- Generally well tolerated
- Mild injection site reactions
- No significant endocrine disruption reported at standard doses
- Headache
- Irritability
- Brain fog during washout period
- Unknown long-term effects (insufficient data)
- Stacks With
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