Tryptophan
Tryptophan is an essential amino acid that the body cannot produce on its own, requiring dietary intake from foods like turkey, eggs, cheese, and seeds. It serves as the primary building block for serotonin, a neurotransmitter central to mood regulation, and melatonin, the hormone that governs sleep-wake cycles. Because of this dual role, tryptophan supplementation has drawn interest for both mood support and sleep improvement.
Expert Evidence
2 references from 1 expert
“I personally have tried taking a supplement which was L-tryptophan, which is the precursor to serotonin. The sleep that I had with increased serotonin by way of tryptophan was dreadful. I fell asleep almost immediately and 90 minutes later I woke up and I couldn't sleep almost for 48 hours.”
Using Science to Optimize Sleep, Learning & Metabolism
1:04:382 references in 2 episodes from 2021
Huberman acknowledges that tryptophan-rich foods can boost serotonin and improve sleep quality for immune function, but he personally tried supplementing with L-tryptophan and had a terrible experience—falling asleep immediately, then waking 90 minutes later and being unable to sleep for nearly 48 hours. He provides no dosage details or broader cautions beyond his own negative experience.
Side Effects
- Drowsiness
- Nausea at higher doses
- Vivid or disrupted dreams
- Gastrointestinal discomfort
- Potential rebound wakefulness