Both increase serotonin and combining them raises the risk of serotonin syndrome.
5-HTP is a direct serotonin precursor. SAMe increases serotonin turnover and receptor sensitivity.
Do not combine these supplements. Choose one or the other, and consult your doctor.
Known drug category interactions for these supplements. Especially relevant if you take prescription medications.
Combining 5-HTP with SSRIs can cause serotonin syndrome.
NEVER combine 5-HTP with SSRIs, SNRIs, MAOIs, or tramadol without direct medical supervision.