Source: Examine.com — Acetyl-L-Carnitine — 1,500–3,000 mg/day of ALCAR in cognition/fatigue trials.
An acetylated form of the amino acid carnitine that crosses into the brain.
Shuttles fatty acids into mitochondria to be burned; the acetyl group also feeds acetylcholine.
Reduced depressive symptoms significantly vs placebo, with efficacy comparable to antidepressants but fewer side effects.
Meta-analysis of 12 RCTs · n=791 · 1–3 g/day — Veronese et al., 2018 — Psychosomatic Medicine (meta-analysis)
Improved cognition in older adults with mild impairment or early Alzheimer's at 12–24 weeks — but the benefit did not hold at 52 weeks.
Meta-analysis of 21 RCTs · n=~1,400 · 1.5–3 g/day — Montgomery et al., 2003 — Int Clin Psychopharmacol (meta-analysis)
Bottom line: The real evidence is in specific groups — depression, and cognition/fatigue in older adults with impairment. For a healthy young person chasing 'energy and focus,' the case is much weaker and mostly anecdotal.
Safe. Can cause GI upset, restlessness or a fishy body odor at high doses.
Anecdotes, not evidence, and not medical advice. Frequency labels are our read of forum sentiment, not a formal survey. Individual responses vary widely.
| Per serving | |
|---|---|
| Typical branded single-ingredient product | $0.50 |
| Bulk powder at the clinical dose (500g, $44.97) | $0.04 |
Buying bulk powder instead of a branded bottle saves about 91% per serving.
Bulk price: $44.97/500g → Alt source: $12.99/250gEducational only — not medical advice. Grades and clinical doses are computed from public labels against sourced research (citations on the main site); prices last verified 2026-07-21. Expensive Powder has no sponsors; bulk links may earn an affiliate commission, which never affects a grade. Talk to a clinician before starting any supplement.