I haven't done Bikram yoga in probably 3-4 months. well yesterday i went to a morning class. i woke up this morning sore. why? cause my body wasn't used to it. it isn't from lactic acid or some other bro science theory. it is no different than when you get into a car accident and are sore from head to toe, or you fuck a chick/guy for an hour and are sore or you do a new type of workout
once your body adjusts you won't be sore anymore.
now that you are sore how do you fix it? time and rest will fix it. sleep as much as you can. a cold bath and hot shower will make you feel better, but it won't speed the process along very much compared to getting proper rest
Sleep, Rest, adequate nutrition, light massage/cardio, stretching.
Supplements that can help reducing the soreness: Vitamin C and D, fish oil, L-carnitine.
Excessive DOMS is not normal. A little is good but excessive is usually a sign something is wrong with your diet/training protocol. I suspect you are probably over training.
Remember the goal of weight training is to stimulate the muscle. Not annihilate it
You dont need to be looking for a supplement. There is no magic cure for soreness. It is pretty normal man. Just ensure you are eating enough protein and getting good rest. That will reduce it. And most of us are eating probably double the protein we actually need so likely your quality of sleep could be better.