What shampoos or conditioners..

Hi Kitty Brite! When people talk about "harsh" ingredients, they typically mean detergents that can dry out hair or other additives that can irritate the scalp. Some of the nice, natural-sounding ingredients can cause more irritation than the synthetic ones.

Sodium lauryl sulfate, TEA-lauryl sulfate and ammonium xylenosulfate are a few surfactant cleansers that can dry out hair and scalp (there are at least half a dozen more but these are rather common.) Do confuse these with sodium LAURETH sulfate, which the FDA and virtually every reputable medical agency considers a mild detergent.

Most conditioners do not contain anything that could wreak havoc on your hair/skin (although sulfur and lemongrass are common offenders.)

Some products can be the gentlest in the world and still won`t work if they aren`t specific to your hair type. What kind of hair do you have--is it fine/thick, dry/healthy, frizzy, etc?