Those unfamiliar with polymorphic serum often believe the churning, neon-green liquid to be toxic or radioactive at first glance. When created, each polymorphic serum is assigned a specific polymorphed form, as described by a polymorph spell of the serum’s level (Alien Archive 2 145). All decisions regarding this polymorph form, such as whether it is a generic or a specific form, are determined when the serum is created. Any creature imbibing a polymorphic serum changes into the serum’s associated form for 2 hours × the serum’s mark (2 hours for mk 1, 4 hours for mk 2, and so on).
If you are unwillingly subjected to a polymorphic serum (such as through a weapon with the injection special property), you can attempt a Fortitude save to negate this effect (DC = 10 + 1-1/2 × the item’s level). If you fail, you can still dismiss the effect as normal for the polymorph spell.
Starfinder Character Operations Manual © 2019, Paizo Inc.; Authors: Alexander Augunas, Kate Baker, Simone Dietzler, Jennifer Dworschack-Kinter, Leo Glass, Sasha Lindley Hall, Amanda Hamon, Vanessa Hoskins, Jenny Jarzabski, Jason Keeley, Lyz Liddell, Luis Loza, Ron Lundeen, Crystal Malarsky, Robert G. McCreary, Conor J. Owens, Joe Pasini, Owen K.C. Stephens, Jason Tondro, and Landon Winkler.