What is the difference between the effects of witchhazel, salicylic acid, and acetasalicylic acid on the face?

Salicylic acid and acetylsalicylic acid are similar molecularly so there is said to be some overlap in function/properties. Salicylic acid is mainly used as a chemical exfoliant, but it's said to have faint topical painkilling and anti-inflammatory properties. Acetylsalicylic acid (aspirin) is mainly used as a painkiller and anti-inflammatory, but it's said to have some exfoliating properties.

Personal experience: Witchhazel - astringent, drying, pore closing. Smells pretty bad. Seemingly incompatible with my moisturizer. Anti-inflammatory (reduces redness). See below. Salicylic acid - commercial anti-pimple stuff, promotes dead skin sloughing, opening clogged pores. A bit expensive to use to fight ingrowns, but for men's facial shaving... it's not unreasonable and can prevent ingrowns for people who are prone for them. I know people with whom this helps (mostly men with very curly facial hair or who had recently started shaving with a razor, as opposed to an electric). Acetylsalicylic acid - asprin. See below. -- I was recommended a recipe for homemade "Tend Skin:" solution 1: 18 tablets uncoated aspirin, crushed in 5 oz. rubbing alcohol solution 2: 8 tablets uncoated aspirin, crushed in 2.5 oz. witch hazel Combine the two, mix well. Personally, I've found that if there's cloudy stuff, it'll settle out if left alone for a day or so, you can decant the clear top portion to another bottle, otherwise, you might can end up with white-ish-powdery-ish residue after you apply. I use disposable cotton pads from the pharmacy. 125 pads for, like, a buck. On sale. You can also use coated asprin; pound the heck out of the asprin tablets in a mortar with a pestle, pick out the papery bits and/or run it through a kitchen mesh-sieve thinger and pick out the papery bits. I had a hard time finding un-coated asprin. ime, helps prevent the redness from shaving of legs, some, but as to actual ingrowns, meh. It's also kind of effective in staving off body acne. The isopropyl alcohol, in addition to the witchhazel, is rather drying. There's something in the witchhazel, though, which causes other stuff like moisturizers to not absorb well. I've asked a couple of ask.me's about ingrowns and hair removal. Haven't found a homerun solution for me. Given that, instead, I've started at-home lasering, and am satisfied thus far (2.5 months into what should take 6+ months; similar timeframe as professional lasering at a fraction of the price) with the current 2012 version 3 Tria laser system. -- As for hyperpigmented spots where ingrowns were, see an immediate previous ask.me answer of mine promoting AHA/glycolic acid. I really think that it helps speed up the rate of depigmentation, and my recommended source is a lot less expensive than the stuff I've found at the pharmacy.

Witchhazel - astringent, drying, pore closing. http://health.howstuffworks.com/skin-care/cleansing/myths/pores-in-hotter-water.htm

The answer also depends on what sort of witch hazel you're using. The less expensive stuff tends to have a much higher alcohol content, and is a lot more drying than the more expensive versions with less alcohol.