5-Hydroxytryptophan(WP) is sold in various places around the world as a dietary supplement that may boost serotonin levels, with possible benefits as a sleep aid, antidepressant, appetite suppressant, and antidepressant.

Everyone appears to respond to 5-HTP differently (and there are woefully few published standardized general trials on the amino acid's function), but I've found that my own body clock seems to respond quite positively to 5-HTP, with no noticeable side effects, and that taking 100mg a day for a week or two makes it much easier for my body to realign back to "wake up early in the morning" after my sleep cycle has been knocked around for an extended period. (Sample size of 1. YMMV.)

Unfortunately, living in Australia, I've always noticed an extra bit of friction whenever I've ordered 5-HTP online (I've never seen it available for purchase anywhere locally in NSW).

  • Some websites will notify me that "this product cannot be shipped to your country" at checkout time or list that they do not ship 5-HTP to Australia in their store policy.

  • A few websites don't make much noise on the subject, accept my order, and ship it off

  • Some sites will feature large Australian flags, draw attention to the fact that they're using AUD$, and drop similar hints, but won't actually say they ship to Australia.

  • A few rare sites explicitly claim that they ship to AU, and don't make much fuss about it.

Why the... weirdness?

I understand the FDA banned L-Tryptophan after linking it to the 1989 Eosinophilia-Myalgia Syndrome(WP) outbreak, then relaxed the ban in 2001, allowing the use of L-Tryptophan (and 5-Hydroxytryptophan, aka oxytriptan).

What happened over the last 19 years though?

Every checkout experience feels like an event horizon, where I know something impactful happened but I can't find or trace the source of the impact.

While I obviously have a bias towards understanding the friction I'm experiencing here in Australia, having a worldwide view would also be very interesting too.

The only reference I've been able to turn up (mostly due to subject ignorance) is https://www.erowid.org/smarts/tryptophan/tryptophan_law.shtml - an old-looking page (apparently last modified 2015) that notes that 5-HTP is "somewhat controlled" in Australia, but doesn't cite why. Some online stores publish similar-sounding positive noises about 5-HTP's controlled status and availability. Wikipedia has no section on *tryptophan's worldwide availability.

I remember reading at some point (I forget exactly where from unfortunately) that Australia generally accepts/allows small quantities of 5-HTP to be imported for personal use, and blocks/turns away larger quantities to prevent resale. I'm curious as to the historical narrative behind why this distinction is made.

Fundamentally speaking, though, why is there friction?

If possible, actual legal citations and references would be awesome.

When I buy 5-HTP, it would be nice to not have to keep making exceptions to my rule about always hunting for whoever has the best going price at any given moment in time. It would be cool if I could online stores concrete references and assuage their fears and concerns.

  • Are you asking about Australia, or the US?
    – user6726
    Aug 26, 2020 at 15:11
  • I'm very interested in Australia's situation because that's where I'm experiencing the ordering difficulties :) but I'm also curious about the worldwide situation too.
    – i336_
    Aug 26, 2020 at 15:13
  • So is your question whether it is illegal in Australia?
    – user6726
    Aug 26, 2020 at 15:14
  • I don't get the impression it's directly illegal per se. At the same time, it feels like its availability is a horribly underdefined grey area. TL;DR I don't know if "illegal" is the correct word or not (it may be :/).
    – i336_
    Aug 26, 2020 at 15:15
  • 4
    I’m voting to close this question because it's about the "why" of a law, which is politics, so it belongs on politics.stackexchange.com Aug 26, 2020 at 16:26

1 Answer 1


From the legal perspective, the question is whether the substance is legal in Australia. The legal root of the matter is the Therapeutic Goods Administration. Dosages above 100 mg are on "Schedule 4" meaning they require a prescription. There are also apparently state regulations. In Queensland, there is an amendment to the

Drugs Misuse Regulation 1987 to ensure that the substance 5-Hydroxy tryptophan (5-HTP) is captured in Schedule 2 with the exception of preparations that contain 100mg or less of 5-HTP per dosage unit

Schedule 2 is "Substances, the safe use of which may require advice from a pharmacist and which should be available from a pharmacy or, where a pharmacy service is not available, from a licensed person". The fact that it is very difficult to verify what the current regulations are may explain the "friction", which may make online purchases difficult.

The underlying reason for government regulation is to keep people safe. Politics SE is an appropriate place to debate the balance between safety and usefulness.

  • Hmm, that's incredibly helpful info. I was able to go find the Poisons Standard from tga.gov.au/publication/poisons-standard-susmp, download it as a PDF from legislation.gov.au, search for "tryptophan", and find "TRYPTOPHAN for human therapeutic use except in preparations labelled with a recommended daily dose of 100 mg or less of tryptophan." This is the exact link I was searching for!
    – i336_
    Aug 26, 2020 at 17:28
  • Also, I commented on the question regarding the difficulty of clarifying "why?" in the sense of understanding, rather than opposing. I'm bad at articulating that. I'd love to learn more about how Tryptophan ended up on the list, but the TL;DR is likely connected to the FDA ban in 1989 in some way, combined with the lack of studies.
    – i336_
    Aug 26, 2020 at 17:30
  • 1
    It's apparently related to a problem of eosinophilia–myalgia syndrome associated with a single source, discussed in ncbi.nlm.nih.gov/pmc/articles/PMC3848710 – i.e. hyper-abundance of caution.
    – user6726
    Aug 26, 2020 at 20:43

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