Drinking a vial causes intense, rapidly increasing pain, followed by a Trigger event. Like any trigger event, it incapacitates any nearby parahumans. If a parahuman drinks a vial, it has no effect whatsoever.
Cauldron generally requires both physical and psychological tests from their customers. Personality, mental state and background have a great deal of effect on the resulting power. Cauldron provides packages to some customers designed to shape their mental state to help guarantee they get the power they desire.
In 1986, two-sevenths of Cauldron subjects died from taking the formula, while four-sevenths experienced unwanted physical changes. Only one-seventh became normal parahumans. However, over time they were able to improve the success rate enormously.
As of 2011, Cauldron vials produced physical or mental alterations akin to the more extreme natural trigger events 0.125% of the time.
Sometimes, especially when the Balance Formula was omitted, they produced more extreme alterations. The Passenger sought to reinforce what it saw as a damaged host. Cauldron referred to these as "deviant cases". 93% of deviant cases had their bodies re-built based on plants, animals, or inanimate objects. Some of these had their memories modified and were released as Case 53s; others were kept prisoner in the Cauldron Compound.
Being under physical stress - increased heart rate etc. - increases the chance of physical mutations. Cauldron customers are told that drinking the vial quickly will produce a cleaner transition, and are expected to drink on an empty stomach. People with a Corona pollentia have a higher risk of deviation.
7% of deviant cases became what Cauldron called "extreme deviants". They resembled nothing found in nature. Cauldron did not usually release these, but studied and then disposed of them. These cases were the usual result of vials containing the Foreign Element.
R refers to the reliability of the sample. Samples with high R values produce simple, predictable results. Samples with low R values risk physical changes, or simply give wildly varying types of powers.
According to Doctor Mother, an R score of 5 indicates a 3-4% chance of unwanted physical changes, and a 0.5% chance of extreme mutations. It also indicates that the sample provides a broad category of powers, rather than a single specific power.
O refers to a power’s "uniqueness", how unusual it is for parahumans to have similar abilities. This value is particularly subjective. Higher ratings in this value make it easier to stand out as a hero or villain, while low ratings give simple powers already possessed by a number of other parahumans.
↑ 1.01.1A metal canister sat on a table [...] The Doctor unscrewed the canister and withdrew a vial. It was no longer than a pen and no thicker than one of the Doctor’s fingers. [...] The Doctor removed the stopper from the top of the vial and carefully handed it over, not letting go until she was sure Jamie had a firm grip. - Excerpt from Interlude 12.5 (Donation Bonus)
↑Vials lined the walls around us, set into an arrangement of metal wires that kept them lined up, multiple vials of the same color lined up beside another arrangement of vials. Except nearly every vial was empty. There was only glass, no fluid inside. Where fluid did exist, the light filtered through and cast dark blotches of color on the gray walls behind. - Excerpt from Venom 29.7
↑Every page was laminated, labeled with a serial number. Each page had a picture of a vial with a different colored metallic liquid inside, sitting beside a list of powers. The bottom half of the page or a second page, depending on the number of powers listed, had a grid with a number assigned to an arrangement of letters.
↑ There is a two month waiting period, during which time I will assign you some testing, some regarding your physical condition, other tests for psychological reasons. [...] The testing will include blood tests, stress tests, MRI, CAT scan, radiographic scans and a Torsten DNA sequencing. These scans are primarily for our purposes, and if you’d prefer, you can have your family doctor arrange or conduct these tests instead for a small fee. A larger fee will allow you to skip the tests entirely. [...] She’d been here twice since her first meeting. Both times, she’d had her psychological testing. She’d also had a full workup done. The psychiatrist had been a young-looking white man, the doctor a heavyset Greek. They’d said little beyond what they needed to for the testing, and had volunteered nothing about Cauldron. She made her way to the room where she’d done her stress test. Here, she’d run back and forth with steadily increasing speeds until she couldn’t run anymore. She’d rested, then run again, then again, until she couldn’t even stand. - Excerpt from Interlude 12.5 (Donation Bonus)
↑“We have options, but I don’t know that they apply to your case. I mentioned the psychological testing earlier. You should know that an individual’s personality, mental state and background do seem to have a great deal of effect on the resulting power. I would even say it’s one of the primary factors, outside of the sample itself.”
Jamie wondered momentarily how her own mental state would influence her powers.
The Doctor went on, “We have a package we call ‘Shaping’, and another we call ‘Morpheus’. Both are intended to make the most of the two month waiting period and help a client reach an ideal mental and emotional state. It’s often purchased by our high-end customers, to refine the powers they want and help ensure there are no untoward effects. For a low-end customer such as yourself, I don’t know that it would suit your needs. You would be buying a lower quality sample to pay for the package… perhaps if you were someone who wanted powers for recreational purposes. If you wanted to help guarantee that you got the ability to fly, for example.” - Excerpt from Interlude 12.5 (Donation Bonus)
↑O refers to a power’s uniqueness. It’s largely subjective, and liable to change through factors entirely out of Cauldron’s control, but it is easier to stand out as a hero or villain if nobody else can do what you do. [...] [With a low O score] your powers would be relatively simple, defaulting to the sort of abilities that countless other heroes already have. - Excerpt from Interlude 12.5 (Donation Bonus)
↑The ‘P’ value is the raw effect of the granted abilities. An estimation of the rating the PRT would assign to the powers. Higher ‘P’, more effective and versatile abilities. - Excerpt from Interlude 12.5 (Donation Bonus)
↑“A power rating of five to Madcap’s seven,” Jamie put her elbows on the edge of the desk and her head in her hands.
“There’s a chance you could get lucky and achieve a power with a greater ‘P’ value than expected.”
Again, that misdirection. Jamie shook her head. “And a roughly equal chance that I could get unlucky, since it’s an average.”
“Admittedly true.” - Excerpt from Interlude 12.5 (Donation Bonus)