Griffonia (5-HTP)

5-HTP comes up in store more often than you'd think. These are the questions our naturopaths ask, and most are about what's permitted here and what's safe with your medicines.

A good fit if

• You've read about 5-HTP overseas and want the evidence straight before you decide anything
• Sleep is your reason, and you're open to a permitted option like theanine, magnesium glycinate or valerian
• Mood is your reason, and you'd like to talk through permitted options like saffron
• You'd rather have a naturopath check your full medicine list than guess

Check with us first if

• You take a Parkinson's medicine containing carbidopa. It changes how much 5-HTP reaches your brain, so it's more than a timing issue.
• You take an appetite suppressant medicine such as phentermine. In an animal study, the combination added to the effect and changed a heart valve measure in rats.
• You already take St John's wort or another product for mood. Stacking products that affect serotonin is how interactions happen.
• You take any prescription medicine. Check with your doctor, pharmacist or our naturopaths before starting.

• Isolated 5-HTP capsules. Best known for: The form used in almost every trial. The largest of them found no benefit over placebo. Absorption: Well absorbed. In that trial, blood 5-HTP and serotonin both rose clearly. Typical use: Trials used 50 to 200 mg a day. It isn't in any Australian listed medicine.
• Griffonia simplicifolia seed extract, sold as herbal 5-HTP. Best known for: The natural source. Seed content varies with where the plant grew, so it's harder to standardise. Absorption: One 20-person trial of an oral spray showed it was absorbed. Typical use: The herb is also missing from Schedule 1, so it isn't a way around the rules.
• 5-HTP with carbidopa. Best known for: Research use with a prescription drug. Never a retail product. Absorption: Carbidopa stops it being converted outside the brain, so more of it reaches the brain. Typical use: Research only. A small trial using it for ataxia found no benefit.
• 5-HTP inside a blend, such as with GABA. Best known for: This is what the one positive trial on falling asleep actually tested, in 18 people. Absorption: Not reported. Typical use: It can't tell you what 5-HTP does on its own.
• L-tryptophan, one step earlier in the same pathway. Best known for: A meta-analysis found less time awake at night at 1 g a day or more, and no change in other sleep measures. Absorption: Not compared with 5-HTP in the evidence we have. Typical use: Also missing from Schedule 1, so it isn't in Australian listed medicines either.
• L-theanine, a permitted amino acid. Best known for: Allowed here (Schedule 1 item 4911), so products can carry permitted sleep and relaxation wording. Absorption: Covered on its own page. Typical use: Capped at 450 mg a day, and the label must say 'Adults only'.
• Saffron (Crocus sativus), a permitted herb. Best known for: Rated (++) in the 2022 WFSBP and CANMAT guidelines, where tryptophan got (+/-). Absorption: Covered on its own page. Typical use: Products can carry permitted mood-balance wording.

Reference values. There isn't one. 5-HTP isn't a nutrient, so the NHMRC sets no recommended intake for it, and there's no such thing as a 5-HTP deficiency.

Typical supplemental range. There's no Australian label dose to compare with, because no listed medicine here can contain it. Trials used 50 mg a day in Parkinson's disease, 100 mg a day in older adults and gym-goers, and 100 mg twice a day in the largest trial. Three trials didn't state a dose at all.

Upper level. None has been set. The highest daily amount studied in people is 200 mg a day for 8 weeks. That's the edge of what's been studied, not a safe ceiling.

Worth knowing. You'll see larger doses quoted on overseas sites. They come from older trials we couldn't check, so we don't repeat them here. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• No food, as a source of 5-HTP itself: it's an in-between compound your body makes, not a nutrient listed in the Australian reference values
• Protein foods, as the tryptophan your body converts (Australia counts tryptophan inside niacin: 60 mg of tryptophan equals 1 mg niacin equivalent)

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• Antidepressants (SSRI, SNRI, tricyclic, MAOI), triptans, tramadol, lithium or St John's wort. Together they risk serotonin syndrome, which is potentially fatal.
• Carbidopa and other Parkinson's medicines. They change how much 5-HTP reaches the brain.
• Appetite-suppressant medicines. The effects add together, and there's a heart valve (mitral valve) signal in rats; this is animal data only.
• Pregnancy and breastfeeding. We found no data.
• Children and teenagers. There's no evidence on dose or whether it works.
• Eosinophilia-myalgia syndrome. The link to 5-HTP is unresolved, not ruled out.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.