NutriStack
5-HTP and L-Tyrosine, a caution.
L-Tyrosine (a catecholamine precursor) and 5-HTP (a serotonin precursor) compete for the same blood-brain-barrier transporter, and unbalanced chronic dosing of one alone can deplete the neurotransmitter pool made from the other.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- 5-HTP and L-Tyrosine
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. L-Tyrosine (a catecholamine precursor) and 5-HTP (a serotonin precursor) compete for the same blood-brain-barrier transporter, and unbalanced chronic dosing of one alone can deplete the neurotransmitter pool made from the other.
Mechanism. Both amino acids cross the blood-brain barrier via the shared large neutral amino acid transporter, so co-timed dosing causes competition for uptake; sustained single-precursor loading can also drive down the opposing catecholamine or serotonin pool.
Recommendation. If using both for mood or sleep, balance the precursors rather than mega-dosing one, and separate intake (for example tyrosine in the morning, 5-HTP in the evening). Avoid this stack entirely if taking SSRIs, SNRIs, or MAOIs.
Minimum separation. 4 hours
Stack Score
How this pair moves the number.
Effect on the composite score
If both 5-HTP and L-Tyrosine are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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