A maximum dosage of 5-HTP has not been established, although health care professionals generally recommend taking 50 milligrams of 5-HTP one to three times per day. However, dosages as high as 150 to 300 milligrams per day have been used for treating depression, reports Everyday Health.
The appropriate dosage of 5-HTP depends upon the user’s current and past health status and age. A health care practitioner can determine a safe and appropriate dosage of 5-HTP to take, states WebMD, as it can be toxic at high doses. Taking high doses of 5-HTP can cause the development of serotonin syndrome, a dangerous condition that involves an excess of serotonin, states Penn State Milton S. Hershey Medical Center.