5-HTP (L-5-Hydroxytryptophan) is a metabolite of L-tryptophan, the amino acid necessary for the synthesis of the neurotransmitter serotonin (3).
- Supports maintaining a healthy weight (ref)*
- Mood support and promotes relaxation (ref)*
- Promotes healthy sleep (ref)*
5-HTP Mode of Action
5-HTP is used to increase serotonin levels in the brain instead of tryptophan because 5-HTP crosses the blood-brain barrier and is directly synthesized into serotonin. L-tryptophan is also converted to 5-HTP (and thus into serotonin) but requires the intermediate step of HTP. Supplementing with 5-HTP is more effective than supplementing with L-tryptophan (1).
As it bypasses the conversion of L-tryptophan into 5-HTP, supplementation with 5-HTP also bypasses the enzyme tryptophan hydroxylase which is involved in limiting the rate of synthesis of serotonin. 5-HTP is effectively absorbed orally, and approximately 70% reaches the bloodstream. It increases the synthesis of serotonin in the central nervous system. 5-HTP and its conversion to serotonin are helpful for sleep because melatonin is a metabolite of serotonin (2). 5-HTP cannot be used to synthesize niacin or proteins like L-tryptophan (3).
Supplemental 5-HTP is produced from the seeds of a tropical shrub, Griffonia simplicifolia (4).
5-HTP is very powerful because of its direct role in serotonin synthesis. Please be aware of the interactions it has with antidepressants and MAOI medications and consult your healthcare practitioner before beginning supplementation if you are on any medications, herbs, or supplements. More info on these interactions is provided below.
Pure Nootropics’ 5-HTP provides 100 mg per 1 capsule. Suggested use in adults is 1 capsule by mouth daily, or as directed by your healthcare practitioner.
5-HTP Side Effects and Toxicity
5-HTP is usually well-tolerated. Side effects may include gastrointestinal symptoms such as nausea, vomiting, gastrointestinal pain, diarrhea or loss of appetite. Side effects are typically seen at higher doses and doses which are increased quickly (4).
A lethal dose was achieved in mice at a dose of 6 g/kg (6).
Take care while supplementing with 5-HTP. Too much serotonin can cause a serious condition known as Serotonin Syndrome, a syndrome usually produced from combining two or more serotonin-increasing medications, supplements, or herbs (5).
A major interaction occurs between 5-HTP and antidepressant medications, such as SSRI’s (like Prozac (fluoxetine), Zoloft (sertraline), Paxil (paroxetine), and others, and tricyclic antidepressants such as Elavil (amitriptyline), Tofranil (imipramine), Anafranil (clomipramine) and others (4).
A major interaction occurs between 5-HTP and MAOI medications, such as Marplan (isocarboxazid), Parnate (tranylcypromine) and Nardil (phenelzine) (4).
Moderate interactions occur between 5-HTP and CNS depressant medications, such as Klonopin (clonazepam), Donnatal (phenobarbital), Ativan (lorazepam), Ambien (zolpidem) and others (4).
Moderate interactions occur between 5-HTP and the medication Lodosyn (Carbidopa); with the medication Robitussin DM and others (Dextromethorphan); with Demerol (meperidine); Talwin (pentazocine); and with Ultram (Tramadol) (4).
If you are taking any herbs and supplements with sedative properties, such as California poppy, calamus, hops, catnip, Jamaican dogwood, St. John’s wort, kava, valerian, skullcap, yerba mansa, and others, 5-HTP may increase sedation (4).
If you are taking any herbs and supplements that increase serotonin levels, such as L-tryptophan, SAMe, Hawaiian baby woodrose, and St. John’s wort, 5-HTP may increase serotonin with adverse effects (4).
For further information, please see our References Tab above.