J.R. Liggett's has been making shampoo bars in a barn in Cornish, New Hampshire since 1982, which is roughly 40 years before 'zero waste' became a marketing category. The formula is simple: saponified olive, coconut, and castor oil, with rose, lavender, and spearmint essential oils. No detergents, no sulfates, no plastic bottle. One 3.5oz bar lasts as long as roughly 24oz of liquid shampoo.

One thing to note: reviewers with normal to thick hair seem to love this shampoo bar, but it may not be great for those with thin, straight hair.