5-HTP is a chemical that the body produces naturally from a protein molecule called tryptophan. 5-HTP is then converted into serotonin, which plays a vital role in nerve cell communication. 5-HTP supplements are used for regulating mood and behavior, sleep, appetite, anxiety and sometimes to lower pain sensation. Venlafaxine is an SNRI anti-depressant, also known as Effexor. The category of anti-depressants known as SNRI, or serotonin-noepinephrine reuptake inhibitors, work by increasing the level of both serotonin and noepinephrine in the brain. 5-HTP and venlafaxine both deal with serotonin levels in the brain, and taking the two at the same time is not recommended, according to Dr. Alan Gaby of ''A-Z Guide to Drug-Herb-Vitamin Interactions.''
Use 5-HTP as directed. 5-HTP is a natural dietary supplement that is normally taken with food for optimal absorption. According to the University of Maryland Medical Center, it has been used to treat a number of conditions, including depression, fibromyalgia, insomnia, migraines and headaches, obesity and hot flashes. Although 5-HTP is not recommended for children, the dose for adults is 50 mg taken one to three times daily. Side effects of 5-HTP are mild and include nausea, heartburn, feelings of fullness and rumbling sensations in some people. Increasing dose with out medical supervision may be dangerous because too much serotonin in the body can become toxic. Consult a physician before beginning to take 5-HTP supplements.
Take venlafaxine only if prescribed. Notify your doctor if you have taken 5-HTP recently or plan to take 5-HTP. SNRI antidepressant drugs are not recommended for children, and the dose for adults is set based on the severity of depression being experienced. With antidepressant use, the dose amount may be changed during the course of use to suit the patient. Always take prescription drugs according to your physician's instructions. Do not take venlafaxine without physician instruction to do so.
Avoid taking 5-HTP supplements while using venlafaxine. Since both of these pills work to increase serotonin in the brain, Gaby says that using them together has an increased risk of the noted side effects for venlafaxine, which include drowsiness, weakness or tiredness, dizziness, headache, nightmares, nausea, vomiting, stomach pain, constipation, diarrhea, gas, heartburn, burping, dry mouth, change in ability to taste food, loss of appetite, weight loss, muscle tightness, twitching, yawning, sweating, hot flashes or flushing, frequent urination, difficulty urinating, ringing in the ears, changes in sexual desire or enlarged pupils. Possible more serious side effects include rash, hives, itching, difficulty breathing or swallowing, chest pain, seizures, unusual bruising or bleeding, small purple spots on the skin, eye pain or redness, changes in vision, fever, sweating, confusion, fast or irregular heartbeat, severe muscle stiffness, fever, problems with coordination, hallucinations and coma. Contact a physician if any of the more serious symptoms noted occur.
- University of Maryland Medical Center: 5-Hydroxytryptophan (5-HTP)
- National Institutes of Health: Venlafaxine
- ''A-Z Guide to Drug-Herb-Vitamin Interactions''; Second Edition; Alan R. Gaby, M.D.; 2006