Keep it simple

Deciding that the vast majority of these are far too broad for you to consider blindly signing up for, you decide to try and keep things simple, sticking mostly to options without guaranteed permanent side effects or pain. Going down the list, you check off a few items near the top of the page: Sexual Enhancement, Increased Arousal, Petite, Extra Thick, and Gender Swap. You were going to leave out the third and fourth items, but figure that they'll most likely just cancel each other out, and want to give the doctor a bit more than just the three she required. You're especially unsure about the final one, but have always somewhat wanted to feel what it's like to be a man, and figure it's one of the last ones without likely side effects.

Signing your name at the bottom, you stand up and walk over to Dr. D, who is rearranging test tubes in a rack. She takes a quick look at your selections and smiles before saying, "Keeping it mostly vanilla, then? Alright, but you'll need to take off that coat, I don't want it ruined." You do as instructed, tossing it over a chair in the corner, and then return to the table, now lying down completely naked.

Turning back to you, she adds, "I'm going to have to strap you in, just as a precaution. Most of your choices are rather tame, but it's mandated by interdimensional safety laws." You simply nod, and she works quickly to tighten a few leather straps around your arms and legs, mostly restraining your movement, but leaving a bit of leeway. "Now then, did you want these in order, or another way?"

"I think we can start with Extra Thick, then Petite, and then in order top-down." Your thought is that you'll get the two options with the most likely chance of side effects out of the way first, and there's a chance the later changes will counteract anything permanent.

"Sounds good to me, I've got those already prepared." Her hooves click against the ground as she walks over to the rack of test tubes, using the clear labels to pull out the proper tube. She returns, and states, "When you're ready, I'll have you drink this, and it's important to drink it all. Just let me know when."

A few seconds pass before you work up the resolve, but then you nod and open your mouth, allowing her to pour the thick liquid directly down your throat. It takes a few seconds, but then a deep warmth spreads through your body, briefly moving throughout your entire skin before centering on your lower body. Your hips and thighs start to swell, pushing you upwards from the table and spreading your legs slightly. It's rather quick, and the warmth fades, its simple task completed.

"Now, normally I would just give someone a dose of Petite to undo that change, but since you want that I'll just give you one and a half. Sound good?" You nod your agreement, still looking down at your much-wider hips. She returns with another tube, and you nod again, allowing her to pour the full tube of liquid down your throat. The change is instant, as you feel almost as if you're compressing in on yourself, the straps instantly loosening around your arms and legs. Your legs actually leave the straps entirely, as they start to move upwards, your body shortening as well.

At the same time, everything about you seems to almost be deflating, your breasts getting smaller, hips and thighs returning to their normal size and then even further past. After several seconds, you're left sitting completely out of the restraints, and you sit up entirely to look at your body. You've shrunk to a height of about five feet, your breasts are tiny A-cups, and your butt is no bigger than a cantaloupe. You feel like you haven't been this small since you were 18 years old.

"Cute, huh? We can made that one permanent later, if you really want. I do have to ask you to sit down, though- we're not quite finished, and this one is tricky to undo." You follow her instructions, and lay back down, positioning your arms and legs in line with the straps. "I'll also have to use a few needles, so I hope that's not a problem."

"That's perfectly fine," you reply, figuring that the situation is crazy enough that a few pinpricks shouldn't matter too much.

The doctor returns, holding a syringe filled with a light red liquid. "This will undo the last change, and I also mixed in the next procedure, to save time." Without any pretense, so as to keep you relaxed for the injection, she slides the needle under the skin of your left arm, pumping the liquid directly into your body.

The sense of warmth returns, and you feel as if the room is shrinking, when in reality you're simply growing, returning to your original size. When you can again feel the leather straps against your skin, the warmth moves upwards, concentrating in the center of your chest. Your breasts, already their original size, start to swell outwards, growing for several seconds before you can feel their weight on your skin. They're likely up to at least full E-cups, and you can't help but shake back and forth a bit, feeling their weight jiggle on your chest.

"Ooh, maybe I'll keep those." The words escape your mouth before you know what you're saying, and Dr. D merely laughs as she replies, "Understandable, but I'll have to revert them to go through the last two procedures. After all, we don't want any extra side effects." You nod in agreement, and she gives you another liquid to drink, your breasts deflating down to their original C size within seconds.

However, you start to feel a deep warmth in your groin, and figure the doctor must have mixed in the arousal potion as well. The walls of your pussy start to feel so sensitive that you could swear you can feel a breeze in the enclosed room, and a steady stream of moisture leaks out, making audible dripping sounds on the table. Dr. D moves down until she's looking up at you, leans over, and simply blows on your exposed cunt.

Instantly, you're driven to orgasm, the walls of your labia contracting, your body writhing in the restraints. A large amount of fluid squirts out, almost hitting the succubus directly in the face. She laughs, clearly pleased that it was successful, and injects another syringe into your leg. Within a few seconds, the heat in your groin fades, and she moves back to the table to prepare the final procedure.

This is the procedure you had the most doubts about, and you start to second guess yourself. You figure it might not be too late to call it off, but this is your only chance.