Things that can lower or block serotonin

June 17, 2026

Last updated: June 25, 2026

Things that can lower or block serotonin:

Aspirin - lowers plasma serotonin

L-theanine - lowers brain serotonin

Thiamine - lowers brain serotonin (in deficiency)

Glycine - lowers brain serotonin

Taurine - lowers brain serotonin

Thyroid hormone T3 - lowers brain and nonbrain serotonin (in hypothyroidism)

Ginger - lowers brain and non-brain serotonin, serotonin synthesis, and blocks serotonin

Cyproheptadine - blocks serotonin

Negative air ions - likely decrease brain and non-brain serotonin

Vitamin E - lowers brain serotonin

Magnesium - lowers brain serotonin (in deficiency)

DHEA - blocks stress-induced serotonin synthesis (higher doses are estrogenic/bad)

Avoiding seed oils - the linoleic acid increases blood serotonin

Eating regularly - prevents excess linoleic acid in the blood

Lysine - blocks serotonin 5-HT4 receptor (GI and mental function)

Progesterone - inhibits serotonin synthesis

Testosterone/DHT - inhibit serotonin synthesis