I have a cool idea. What if, when under the effects of potions, the altering chemicals attach to the genetic coding inside your reproductive cells temporarily, and if an attempt at breeding is successful, the child will have the effects of the potion applied permanently. If one parent consumes a potion, the potion will only affect the baby at half efficiency. If both parents consume the same potion, the baby will have full potion potency applied permanently. Once the potion wears off, the chemicals detach from your sperm/egg cells. If the potion wears off during pregnancy, the baby is still affected at full force. If you continually drink the potion, the effects on the baby will build and build without limit. Fascinating, no?