FGFR3 Inhibitors
Also known as TYRA-300, infigratinib, erdafitinib, FGFR inhibitors
Investigational and oncology drugs that circulate in height communities. This entry exists to be clear about why that is a genuinely dangerous idea.
Not purchasable for this purpose. Erdafitinib is dispensed through oncology pharmacy at oncology prices.
How it works
FGFR3 signalling restrains chondrocyte proliferation at the growth plate; overactivation causes achondroplasia. Selective FGFR3 inhibitors such as infigratinib and TYRA-300 are in clinical trials aimed at that condition in children. Erdafitinib is a broad FGFR inhibitor approved in oncology for urothelial carcinoma — a cancer drug, not a growth drug.
How it's used
These are trial drugs and chemotherapy agents. TYRA-300 and infigratinib are investigational and available only through clinical trials in defined paediatric populations. Erdafitinib is prescribed by oncologists with intensive monitoring. In an adult, growth plates are fused, so no FGFR3 inhibitor can add height — the tissue it acts on no longer exists. Anything sold online under these names is not the real drug, and if it were, that would be worse.
Trade-offs
In favour
- Legitimate, promising research direction for achondroplasia in children
- TYRA-300 and infigratinib are in genuine regulated trials
Against
- No adult height application — the biology forbids it
- Erdafitinib is an oncology drug with severe toxicity
- Not obtainable legitimately outside trials or oncology care
- Grey-market versions are almost certainly counterfeit
Risks and side effects
- Erdafitinib causes central serous retinopathy and retinal pigment epithelial detachment — real, sight-threatening eye toxicity
- Severe hyperphosphataemia with soft-tissue and vascular mineralisation
- Nail and skin toxicity, stomatitis, hepatotoxicity
- Growth plate and skeletal effects are unpredictable outside the studied population
- Taking an unmonitored FGFR inhibitor for cosmetic height is one of the most dangerous ideas in this library, and it cannot work in an adult regardless
How good is the evidence?
Strong and growing trial evidence for FGFR3 inhibition in paediatric achondroplasia. Zero evidence, and no plausible mechanism, for adult height gain. Included here because the misuse is real, not because the use is.
Sources
- FGFR3 inhibition in achondroplasia — trial literaturePubMed
- Erdafitinib prescribing informationUS FDA
Sources point to guideline bodies and literature searches rather than single papers, so they stay accurate as the evidence moves.