Nootropic
S-Phenylacetyl L-Glutathione
Also known as: S-Phenylacetyl Glutathione, SPAG, Phenylacetyl Glutathione, N-Phenylacetyl-L-Glutathione
S-Phenylacetyl L-Glutathione is a modified form of glutathione designed for improved bioavailability and potential blood-brain barrier penetration. Limited human evidence exists; most data is from cell culture and animal studies.
Primary uses
- Cognitive support
- Antioxidant defense
- Neuroprotection
How it works
- Delivers glutathione or its precursors across the blood-brain barrier
- May enhance intracellular glutathione levels
- Potential antioxidant and free radical scavenging activity
Dosage
- Typical range
- 200-400 mg daily
- Timing
- No established optimal timing; morning dosing suggested
- With food
- May be taken with or without food
- Duration
- Long-term safety and efficacy duration unclear due to limited research
- Special populations
- Insufficient data for pregnant/nursing women, children, or those with severe liver disease
Forms
- Capsule· 70/100
- Powder· 70/100
Safety
Common side effects
- Generally well-tolerated; specific adverse event data limited
Contraindications
- Caution in individuals with severe liver or kidney impairment
- Insufficient safety data in pregnancy and lactation
Evidence notes
Very limited human clinical data. Mechanism is theoretically sound but empirical evidence in humans is sparse. Most supporting evidence comes from in vitro studies and animal models. No large RCTs in human populations.
Grade D: Primarily pre-clinical or anecdotal; human efficacy not established.
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