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TRH (Thyrotropin-Releasing Hormone)
It was a real, approved diagnostic agent — as protirelin, marketed as Thypinone and Relefact TRH — used to test pituitary TSH response. The only FDA-approved US preparation stopped being manufactured in 2002. There's no dedicated human trial supporting the cognitive, anti-aging or wellness uses it's now sold for in some longevity clinics.
In brief
Should you care? Yes, if you've heard it pitched at a longevity clinic for cognitive or anti-aging effects — the diagnostic approval it once had never tested for that use.The short version
- Genuinely approved once, as a diagnostic test for pituitary/thyroid function.
- US manufacturing stopped in 2002 — no FDA-approved product is currently marketed here.
- No dedicated trial supports the cognitive/anti-aging wellness use it's sold for today.
What it is
TRH (thyrotropin-releasing hormone) is a hypothalamic tripeptide that stimulates TSH and prolactin release from the anterior pituitary. Protirelin is its synthetic pharmaceutical form.
Its real approval history
Approved in the US as a diagnostic adjunct — marketed as Thypinone and later Relefact TRH — for assessing thyroid and pituitary function (for example in suspected secondary hypothyroidism or acromegaly), given as an IV test dose with TSH measured afterward. Manufacturing of the branded US preparation stopped in 2002, and the diagnostic TRH stimulation test is largely no longer available in the US as a standardized commercial product, per pharmacology-reference reporting; we did not independently locate the specific FDA discontinuation notice, so — as with gonadorelin's page — this should be read as well-supported by secondary sources rather than a directly quoted primary finding.
What it's sold for today
Some longevity and wellness clinics now use TRH off-label for claimed cognitive, mood or anti-aging effects. We did not find a dedicated clinical trial testing TRH for any of these uses — the same pattern this site's sermorelin page describes: a real approval doesn't transfer to a different, untested use.
Safety notes
As a hormone that directly stimulates TSH and prolactin release, off-label or unsupervised use carries a real, mechanistically grounded risk of disrupting thyroid and prolactin balance — worth flagging even without a dedicated safety trial for the wellness use, since the mechanism itself isn't inert.
References
- Protirelin/TRH diagnostic use and discontinued US manufacturing, per Drugs.com and NCATS Inxight Drugs reference summaries — no primary FDA discontinuation notice independently located.