Medical disclaimer: SnoozeVerdict summarizes what people say about sleep supplements on Reddit. It is not medical advice, and nothing here is meant to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the Food and Drug Administration. Talk to your doctor or pharmacist before starting a supplement, especially if you are pregnant, take medicines (including sleep or mood medicines), or have a medical condition. Poor sleep that lasts for months, loud snoring or gasping at night, or falling asleep during the day while driving or working needs a doctor, not a supplement. Full disclaimer.
Amino acids · Falling asleep

Best Amino Acid Supplement for Falling Asleep: What Reddit Owners Report

Among amino acid supplement options, L-theanine has the best reports from people who struggle to fall asleep: 23 of 27 rated owner comments were positive. We rank by a context rating that pulls small samples toward the average, so a handful of glowing comments cannot top the list. Only options with at least 5 rated comments in this context are ranked. This is a summary of self-reports, not a recommendation, and it is not evidence that any of them works for you.

#SupplementContext ratingRated comments herePositiveNegativeUnwanted effectsOverall score
1L-theanine3.82723203.8
2Glycine3.7118203.9

Also mentioned, but with fewer than 5 rated comments in this context (not ranked): 5-HTP, L-tryptophan, Taurine, GABA.

Why each ranks where it does

1. L-theanine

23 positive and 2 negative out of 27 rated comments from people who struggle to fall asleep; 85% positive. See L-theanine side effects. How people take it: L-theanine dosage and timing.

4/5 Falling asleep fasterTaste & form

“I've been taking l-theanine for like 8 years now, no side effects, withdrawls when I stop, or anything negative from it at all.”

owner comment via r/Nootropics · 2026-06-26 · 8 upvotes
2/5

“Unfortunately I took l theanine out of desperation last night and I've read you have to go complete cold turkey on it for at least 10-15 days to return back to normal.”

owner comment via r/sleep · 2026-06-20 · 1 upvotes

2. Glycine

8 positive and 2 negative out of 11 rated comments from people who struggle to fall asleep; 73% positive. See Glycine side effects. How people take it: Glycine dosage and timing.

4/5 Falling asleep faster

“I take 3g before bed with mag glycinate, and that double-tap on my glycine receptors really helps me fall asleep”

owner comment via r/Supplements · 2026-05-13 · 3 upvotes

Safety notes

Check interactions with a pharmacist before starting, and see a doctor about new or severe symptoms.

Example L-theanine products

Examples sold on Amazon, not ranked by Reddit. The score above is for the ingredient, not these products.

Example product · not Reddit-scored

Swanson Suntheanine L-Theanine Supplement, 200 mg (60 Vegan Capsules), Double-potency supplements

$16.49 on Amazon (price as of 2026-11-03). Prices change; check Amazon for the current price.
Example product · not Reddit-scored

THORNE Theanine, 200 mg L-Theanine Supplement, 90 Capsules

Brand on Reddit: 3.6 from 11 owner comments · Thorne owner reviews
$68.00 on Amazon (price as of 2026-11-03). Prices change; check Amazon for the current price.

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