I've heard a bunch of various recipes for lean, containing a variety of ingredients, tho most recipes I've heard generally call for hydrocodone (both in powdered pill form and Tussionex syrup) or codeine,or both. I've also heard of oxycodone in some recipes, but they all call for some kind of opioid, promethazine, alcohol ( I've heard of people using liquor[normally vodka], Loko/Joose/Blast/Boss, etc......), some people use quetiapin (Seroquel), benzos (usually Xanax), and various pharmaceuticals. Just for curiosity's sake, what's in the lean you drink?
I'm going to assume that you have Tylenol 3 with codeine as to which pills you're asking about, since I have yet to hear of a 325mg codeine pill. Those have 30mg of codeine in each pill. As others have said, it's anyone's guess as to your opioid tolerance, personal body chemistry, metabolism, height, weight, body mass index, whether you take them on an empty or full stomach, and the lots and lots of factors that are important when determining how you will respond to a given amount of a given drug. When I was 15, I already had a pretty good size opioid tolerance. Whatever your tolerance, codeine is generally regarded as a "baby" opiate, good for antitussive qualities but it takes most opioid users a large dosage amount to get nice and high. I would do a CWE on them as others have advised, whatever the amount you take, because the amount required to get high will include a lot of APAP. On a side note, if you are 15 and don't actually need it, I would think twice about starting on the opioid road so young. I wish I would have because I have been a chronic pain patient for more than 20 years and, due to my extensive use of large, high dosage amounts of powerful opioids (I started on pills younger than you and by 16 I was injecting heroin), it requires a lot of powerful opioids (I am prescribed roxy 15s and need more and stronger opioids than what I'm getting prescribed) due to my tolerance levels. Just something to keep in mind because 1). opioid WDs are hell on Earth and 2). If you ever need opioids, it will take a lot more to do the job.