glycerine: has many many uses, and is a hygroscopic that can loosen up nasal congestion, used for numerous skin related issues, calluses inflimmation, skin moisturizer, it also is said to eliminate a lot of bacteria by absorbing the water they contain, ppl use it as a mouth wash, also used in most food products and toothpaste as a bonding agent and sweetener...a good reason ppl get dry mouth from vaping
Propylene glycol: used in medical applications asthma inhalers, injectable medications, smoke machines, antifreeze and hydrolic equipment, widely used as a food additive...also does cause allergic reactions in some ppl, so that soar throat can be attributed to this if the problem doesnt go away after about a week, I studied this in college chemistry, it actually metabolizes like sugar creating energy, not sure if those properties are continued wen vaping.
nicotine: shown to be more addictive than ...... or ......., releases dopamin into ur neurotransmitters, creating feeling of either a stimulant or relaxer...ur brain actually becomes used to the nicotine and adjusts to it meaning over time u will need more to feel the same efffects, similar to most narcotics...p.s. in pure form nicotine is deadly through jsut skin contact, full chemical suits and ventilation hoods in labs are used wen handling pure or near pure nicotine.
hope the info helps lulubell....i left out a few things about all three but i would end up writing a masters thesis paper on a forum reply lol.