Should be able to activate them by having mark take both the mother and sister and then speaking to the father to get them back. Note, you need to have one of the hormones on hand and lower strength than mark, then its legit just spamming the outcome until mark gives you a choice.
edit: you and the father need lower strength than mark, idk if the father having more strength than you influences the RNG chance of mark giving you the option or not.
I think it would be cool if being spiked didn't require you to buy 2 of the hormone packets. I just would feel better if Stephen was the one that escalated things.
Also, surely at 100 strength with tons of fighting experience, fem mc can eventually fight off either Mark or Stephen. Also, bonus points if femMC had a different victory graphic over random zombies.