All told, Jenna got over the initial shock of Mary's appearance pretty quickly. Mary was much, much sexier than she'd been a few days ago, and mostly that's all Jenna noticed. It seemed to Mary that she should ease her friend into the situation, and bigger tits was a simple enough entry point.
Before long they were poking through the vials together, and Jenna was starting to notice some of the options. She asked, "Wait, there's vials in here for animals, for shrinking and growing, even super crazy stuff like being made of rubber. How could this possibly work?"
Mary shrugged. "No idea, but I think I believe it. Magic, I guess."
"We've got to try a few of these. Is it reversible?"
Jenna wasn't totally sure, but she replied, "As far as I can tell, worst case you take a couple doses of Human Female and it should put you back to normal. There's a few of them that seem like they're kind of meant as a reset, if that makes sense. Like here's one that's just Human, no gender or anything."
"Wow. We have to try some of these," said Jenna.
"Well, to be honest," said Mary, "I kind of did just before you got here."
Jenna looked Mary up and down again, seeming to search for more differences. She didn't see anything obvious. Jenna said, "Huh, you're not obviously, uh, non-human looking. Now that I look again maybe you're skin tone is a bit off..."
"They go pretty slow," Mary replied. "In fact last time it mostly happened when I went to sleep. But look, I do have the start of a tail!"
Mary pulled down the back of her pants, showing her friend the slender tail that extended perhaps six inches downwards. It was still mostly just skin color, but was a couple inches longer than it had been.
Jenna furrowed her brow at it. "Woah, it really does work," She said, before asking, "What did you take?"
"I picked one of the dinosaurs, and I did it at random, I don't even know which one. I wanted to try it and it seemed like fun at the time, but now I'm starting to wonder."
"God, that sounds like you. That's so crazy. Let me join in," said Jenna.
"I took about half so should end up, uh, sort of a blend. Like should keep my hands, that sort of thing."
Jenna was insistent, "I'm in, I'll do the same thing."
Mary beamed, so glad her friend wasn't freaked out. "I'd love that. What do you want to be?"