When your have a clogged sink drain, you reach for your plumbers helper, don't you? (Find out if you're using your toilet plunger the right way.)
I wish that unclogging a drain was really that simple. The problem is that smooth-wall pipes like ABS, or PVC don't catch much hair. Coarse wall pipe like cast iron and galvanized iron pipe catch hair so well that a vigorous plunging won't loosen it.
Instead, the plunging action causes the normal slime of soap scum and skin cells on the interior of the pipe wall to come loose. It then drops down the drain and completes the stoppage at the hair plug. Thus a slow drain that was only a nuisance becomes a totally stopped drain that is an emergency.
For this reason I recommend against using a plumbers helper on lavatory, tub or shower drains.
The sad fact is this... using that plumbers helper is probably not going to help. So the next thing you'll try is Liquid Plumber or another chemical drain cleaner. If you go this route, at least do it while the drain still works a little. That way the chemical will be drawn past the clog.
Hair is protein, and won't dissolve with boiling water, lye, or soda. It may be “digested” with some enzymatic products, but I don't have any to recommend. Frankly I haven't done the research because I own a drain snake and I use it.
When I want to learn more about anything I go to Wikipedia. I would recommend that as a starting point for tips on chemicals. In the future I may submit something more definitive, but my feeling is that I don't get sick or burned when I use my drain snake to clear a clogged drain. It is always faithful to clear hair from a drain.
As a plumber, my biggest problem with chemicals is this... if they don't work for you and you call us, we have to use our drain snake. Then the caustic chemical soaks into our tool's cable drum and splashes all over us.
What you put down your drain only you can control. But if you DO use chemicals like Liquid Plumber or others and then call a plumber because it didn't work, have a heart! Be kind enough to inform your plumber about what you've tried before he or she begins to work. Then they may don whatever safety gear they carry for that purpose. They will figure it out anyway, but by then it might be a problem.