protirelin

The story

1. Proto-Indo-European*péh₂wr̥
2. Proto-Hellenic*pāwər
3. Ancient Greekπῦρ (pûr)
4. Ancient Greekπῠρρός (pŭrrhós)
5. GermanPyrro
6. Englishpyrrole
7. Englishpyrrolidine
8. Englishproline
9. Proto-Indo-European*dʰwer-
10. Proto-Hellenic*tʰurā
11. Ancient Greekθῠ́ρᾱ (thŭ́rā)
12. Ancient Greekθῠρεός (thŭreós)
13. Proto-Indo-European*weyd-
14. Proto-Indo-European*wéydos
15. Proto-Hellenic*wéidos
16. Ancient Greekεἶδος (eîdos)
17. Ancient Greekθῠρεοειδής (thŭreoeidḗs)
18. New Latinthyreoīdēs
19. Englishthyroid
20. Englishthyro-
21. Proto-Indo-European*trep-
22. Ancient Greekτρέπω (trépō)
23. Ancient Greekτροπή (tropḗ)
24. Ancient Greekτροπῐκός (tropĭkós)
25. Englishthyrotropin
26. Proto-Italic*wre-
27. Latinre-
28. Old Frenchre-
29. Proto-Indo-European*(s)leg-
30. Proto-Indo-European*(s)leg-s-ós
31. Latinlaxus
32. Latinlaxō
33. Vulgar Latin*laxicāre
34. Vulgar Latin*lassicāre
35. Old Frenchlaschier
36. Old Frenchrelaschier
37. Old Frenchrelaisser
38. Middle Englishrelesen
39. Englishrelease
40. English todayprotirelin

From Translingual Pro + English -tirelin (“thyrotropin releasing hormone analog”).