5-HTP (5-Hydroxytryptophan, L-5-Hydroxytryptophan)


5-HTP is the precursor of the neurotransmitter serotonin. Commercially available 5-HTP is obtained from the seeds of the plant Griffonia simplicifolia.
5-HTP has been suggested as a treatment for many conditions. Some research supports the use of 5-HTP in treating cerebellar ataxia, headache, depression, psychiatric disorders, and fibromyalgia, and as an appetite suppressant or weight loss agent. There is insufficient scientific evidence to support the use of 5-HTP for any other medical condition.
5-HTP may cause gastrointestinal disturbances, mood disturbances, seizure, or abnormal blood counts. Some side effects might result from contaminants in 5-HTP products.

Related Terms

5-Hydroxytroptophan, Griffonia plant seed extract, Griffonia simplicifolia, L-5-HTP, L-5-hydroxytroptophan, Natrol® 5-HTP, Natural Factors® 5-HTP, oxitriptan, serotonin, Tript-OH®, tryptophan.
Select combination products: Gabadone™ (5-HTP, tryptophan, and other amino acids), Nature's Way 5-HTP (5-HTP, vitamin B6, vitamin C), Natural Factors® Tranquil Sleep (5-HTP, melatonin, L-theanine).
Note: 5-HTP should not to be confused with L-tryptophan.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Cerebellar ataxia (Grade: B)
5-HTP has been observed to have benefits in some people who have difficulty standing or walking because of cerebellar ataxia. However, current evidence is mixed.
Obesity (Grade: B)
Studies suggest that 5-HTP may reduce eating behaviors, lessen caloric intake, and promote weight loss in obese individuals.
Alcoholism (withdrawal symptoms) (Grade: C)
Early research suggests that 5-HTP may lessen alcohol withdrawal symptoms. Further research is needed before a conclusion can be made.
Anxiety (Grade: C)
Although 5-HTP has been proposed as a possible treatment for anxiety disorders, sufficient human evidence to make a firm conclusion is lacking.
Depression (Grade: C)
The results of numerous studies in humans suggest that 5-HTP may aid in the treatment of depression. However, it is not known whether 5-HTP is as effective as commonly prescribed antidepressant drugs.
Down's syndrome (Grade: C)
Preliminary research on 5-HTP in children with Down's syndrome has yielded insignificant results. Further research is necessary.
Fibromyalgia (Grade: C)
There is a small amount of research evaluating the use of 5-HTP for fibromyalgia. Early evidence suggests that 5-HTP may reduce the number of tender points, anxiety, and the intensity of pain, and may improve sleep, fatigue, and morning stiffness. Further research is needed before a conclusion can be made.
Headache (Grade: C)
Several studies, in both children and adults, suggest that 5-HTP may be effective in reducing the severity and frequency of headaches, including tension headaches and migraines. Further research is needed.
Mood (Grade: C)
In early research, 5-HTP lacked an effect on mood in healthy, young subjects. However, in this population, 5-HTP may impair decision-making. Further well-designed research is needed.
Neurologic disorders (Grade: C)
5-HTP has been studied in panic disorder and various neurologic disorders. Additional clinical research is needed before conclusions can be made.
Parkinson's disease (Grade: C)
Parkinson's disease is a neurological disorder that usually develops around the age of 50. The disorder occurs when the brain cells that make dopamine slowly degenerate. Symptoms include tremors (shaking) and difficulties with movement and coordination. 5-HTP has been studied, usually in combination with drugs, for Parkinson's disease.
Psychiatric disorders (Grade: C)
It has been suggested that 5-HTP may reduce psychotic symptoms and mania in panic disorder, but studies in people with schizophrenia have shown mixed results.
Sleep disorders (Grade: C)
Insufficient evidence is currently available regarding the use of 5-HTP for sleep disorders. Additional studies are needed before a conclusion can be drawn.
Hot flashes (Grade: D)
Limited research suggests that 5-HTP may be ineffective for reducing hot flash frequency in postmenopausal women. Further research is required before firm conclusions can be drawn.
Seizures/epilepsy (myoclonic disorders) (Grade: D)
Although 5-HTP has been studied as a treatment for various myoclonic syndromes and epilepsy, available research does not support the use of 5-HTP for these conditions.