Hm

code/game/objects/items/stacks/medical.dm

@@ -72,6 +72,8 @@
 			to_chat(user, "<span class='notice'> [M] is at full health.</span>")
 			return FALSE
 		user.visible_message("<span class='green'>[user] applies \the [src] on [M].</span>", "<span class='green'>You apply \the [src] on [M].</span>")
+		if(AmBloodsucker(M))
+			return
 		M.heal_bodypart_damage((heal_brute/2))
 		return TRUE
 	if(iscarbon(M))
@@ -148,6 +150,8 @@
 		return
 	if(iscarbon(M))
 		return heal_carbon(M, user, 0, heal_burn)
+	if(AmBloodsucker(M))
+		return
 	to_chat(user, "<span class='notice'>You can't heal [M] with the \the [src]!</span>")
 
 /obj/item/stack/medical/ointment/suicide_act(mob/living/user)