Also I have a safety concern using biodegradable soaps because some of them are very fragrant and may be an attractant for bears. Be sure to put your soap in your bear bag. If you are counting ounces to keep your pack light make sure to repackage your soap in a smaller container. Remember most biodegradable soaps are super concentrated and it only takes a few drops per use to get clean.
That being said here are a few biodegradable soap brands I have experience with:
Sea to Summit Wilderness Wash ReviewPro's: not super fragrant, smaller 1.3 oz bottle (40mL), secure bottle top, only need small amount for washing up
Con's: made in China
Specs: is phosphate free, biodegradeable, concentrated liquid, all purpose, use in fresh or saltwater, lo-sudsing, HDPE 2
Instructions on bottle: Use at least 100 meters (328 feet) from natural water sources. Use 1 cap full (3-5mL) for an average shower.
Ingredients: disodium ethylenediamine tetraacetate, sodium laureth sulfate, isothiazolinone chloride, coconut diethanol amide, sodium chloride, acetate chlorhexidine, glyceryl cocoate, lauryl hydroxy sulfobetaine, sodium lauroyl sarcosinate
Where to Find: REI, Amazon
Campsuds with Citronella, Lavender, and Peppermint Oils ReviewPro's: Made in the USA, pleasing smell, a little goes a long way
Con's: 4oz (120mL) container is too big for backpacking, top spout style can leak, too aromatic... can smell outside bottle
Specs: phosphate free, biodegradable, all purpose, concentrated liquid, use in fresh or salt water, HDPE 4
Instructions on bottle: Use at least 200 feet away from lakes and streams. Dig a hole 6-8" deep to dispose of soapy rinse water. This allows soil bacteria to completely biodegrade Campsuds.
Ingredients: blend of purified water, vegetable based biodegradable anionic and non ionic cleaning agents and natural fragrance oils
Misc Info: The Original Campsuds brand is available in 2 oz size up to gallon bulk sizes
Where to Find: REI, Amazon, or any major outdoor store