As a 48 year old with many years of sun damage and those pesky newly appearing age spots, I decided to uncover some new skin without the high price of a spa or dermatologist. You CAN do it safely if you are very careful.
Start with only a 12.5% solution (a small bottle of this can be found online for about $25). Begin with only a one layer peel the first time. Complete instructions are usually included....always follow them! If you do okay with a 1 and 2 layer peel, you can add layers each subsequent treatment, spaced 3 weeks apart. You will eventually know how much your particular skin can tolerate. I have not done more than a 3 layer peel.
Never buy a strong solution. There are horror stories out there of people using 50 and 100% TCA, with terrible consequences, including permanent scarring.
Just as a guideline, I only dip my Q-tip into the the solution once for a single layer on my whole face. Always wait 5 minutes between layers. I have also done 3-layer spot treatments on age spots -- it takes a few treatments for them to completely disappear. A small bottle of the solution should give you many muti-layer treatments, saving you $100's over going to a specialist.