Glycine and L-Tryptophan
Glycine (inhibitory) and tryptophan-derived serotonin/melatonin work through complementary pathways to support sleep.
Glycine
A calming amino acid for sleep, collagen, and metabolic health.
L-Tryptophan
The dietary precursor to serotonin and melatonin.
Great to combine
These two are frequently stacked together; they complement each other and are commonly taken at the same time.
How to take them
Glycine
- Dose
- 3 g before bed for sleep; up to 10 g/day for collagen support
- Timing
- 30–60 minutes before bed for sleep; with meals for collagen/metabolic goals
L-Tryptophan
- Dose
- 500–2,000 mg per day
- Timing
- Evening on an empty stomach, or with a small carbohydrate snack to improve brain uptake
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Frequently asked
Can you take Glycine and L-Tryptophan together?
Yes, they are commonly taken together. Glycine (inhibitory) and tryptophan-derived serotonin/melatonin work through complementary pathways to support sleep.
What's the best time to take Glycine and L-Tryptophan?
Around the same time works well. Glycine: 30–60 minutes before bed for sleep; with meals for collagen/metabolic goals. L-Tryptophan: Evening on an empty stomach, or with a small carbohydrate snack to improve brain uptake.
How do Glycine and L-Tryptophan interact?
Synergy: Work better together than alone. Glycine (inhibitory) and tryptophan-derived serotonin/melatonin work through complementary pathways to support sleep.
Related pairings
Glycine + Magnesium
A sleep pairing with a built-in shortcut: magnesium glycinate is magnesium bound to glycine, so that form already delivers both. A standalone 3 g dose before bed (the amount sleep studies used) tops up the glycine, lowering core body temperature while magnesium relaxes muscles and calms the nervous system.
Glycine + NAC
NAC provides cysteine while glycine provides another rate-limiting precursor; together they are more effective at raising glutathione than either alone (GlyNAC protocol).
Collagen + Glycine
Glycine makes up about a third of collagen, so supplementing it provides raw material that collagen synthesis depends on.
Creatine + Glycine
Glycine is one of the three amino acids the body uses to synthesise creatine endogenously.