gonadorelin

The story

1. Proto-Indo-European*ǵenh₁-redup.
2. Proto-Indo-European*ǵíǵn̥h₁eti
3. Proto-Hellenic*gígnomai
4. Ancient Greekγίγνομαι (gígnomai)
5. Ancient Greekγονή (gonḗ)
6. New Latingonadēs
7. Englishgonad
8. Englishgonado-
9. Proto-Indo-European*trep-
10. Ancient Greekτρέπω (trépō)
11. Ancient Greekτρόπος (trópos)
12. Latintropus
13. Englishgonadotrope
14. Englishgonado-
15. Ancient Greekτρέπω (trépō)
16. Ancient Greekτροπή (tropḗ)
17. Ancient Greekτροπῐκός (tropĭkós)
18. Englishgonadotropin
19. Proto-Italic*wre-
20. Latinre-
21. Old Frenchre-
22. Proto-Indo-European*(s)leg-
23. Proto-Indo-European*(s)leg-s-ós
24. Latinlaxus
25. Latinlaxō
26. Vulgar Latin*laxicāre
27. Vulgar Latin*lassicāre
28. Old Frenchlaschier
29. Old Frenchrelaschier
30. Old Frenchrelaisser
31. Middle Englishrelesen
32. Englishrelease
33. English todaygonadorelin

From gonado(tropin) + -relin (“LHRH release–stimulating peptide”).