Peptide Graded

Trofinetide (predecessor programs)

Is Trofinetide (predecessor programs) legal in the US?

No. It is approved only for Rett syndrome. Fragile X and brain injury uses are not approved.

BSome human evidenceFDA approvedas of 2026-10-26

Trofinetide is approved by the FDA as Daybue (March 2023) for Rett syndrome in adults and children 2 years and older. The earlier programs covered here, in fragile X syndrome and traumatic brain injury, were investigational and did not lead to approval. 34

No. Its only approved use is Rett syndrome in patients aged 2 and older. Any use for fragile X, brain injury or other conditions is off-label. The fragile X evidence is a single 28-day phase 2 trial. 34

Read the full Trofinetide (predecessor programs) page

More on Trofinetide (predecessor programs)

Citations

  1. Berry-Kravis 2020, Pediatric Neurology: randomized placebo-controlled phase 2 trial of trofinetide in fragile X syndrome doi.org
  2. Neul 2023, Nature Medicine: Trofinetide for the treatment of Rett syndrome, phase 3 LAVENDER trial doi.org
  3. FDA 2023: Daybue (trofinetide) approval label accessdata.fda.gov
  4. DailyMed: Daybue (trofinetide) current prescribing information dailymed.nlm.nih.gov
  5. Wei 2009, J Neuroinflammation: NNZ-2566 inhibits neuroinflammation after penetrating ballistic-like brain injury in rats pubmed.ncbi.nlm.nih.gov

Reference information only, not medical advice. Drawn from the Trofinetide (predecessor programs) article, fact-checked against the cited sources. No dosing anywhere on this site.