Jheri Redding was already a big name in hair care when he started Nexxus. He had founded Jheri Redding Products in 1956, Redken in 1960 and Jhirmack in 1968, according to his 1998 obituary in The New York Times. In 1979 he started again, this time as a family business, and called it Nexxus.

Redding said the name stood for Nature and Earth United With Science, an acronym with an extra x for good measure. The brand also says the word means connecting or binding together in Greek. Either way, it tells you what he cared about. He is credited with pushing pH-balanced shampoos, adding vitamins and minerals to hair care, and treating hair with protein, ideas that sound obvious now and were not then.

You can still see that protein thinking in Nexxus shampoo today. Almost every line talks about keratin, elastin or amino acids, and the brand calls its routines proteomic regimens, which is a very Nexxus way of saying a shampoo and conditioner that work together.

The first grid is five Nexxus shampoos and three dry shampoos. The second is the conditioners, a leave-in treatment and a lightweight oil.

My one rule with protein-heavy lines: if your hair starts to feel stiff or straw-like, you have overdone it. Swap in a moisture conditioner for a few washes and it comes right back.

Nexxus names each line for a technology, so here is what each bottle actually does. Every one of them has a matching conditioner in the next grid, which makes building a routine easy.

Keraphix Damage Repair Shampoo is the one for damaged hair, part of the brand's keratin repair routine with liquid crystal amino acids. It is the purple bottle with the pump, and it is where I would start if your hair has been bleached or flat-ironed a lot. Color Assure Vibrancy Shampoo is the magenta one, made to seal in color and slow fading. Hy-Volume Shampoo uses hyaluronic acid and promises 48 hours of lift for flat hair.

Clean & Pure Nourishing Detox Shampoo is a lightweight detox formula with elastin protein and marine minerals, good for oily roots. Ultralight Smooth is sulfate free and made for hair that frizzes, and it has a loyal following for how soft it leaves hair.

Then there are three dry shampoos: Advanced Invisible Clean, a Brunette version for dark tones, and Volume Refresh, which adds lift at the root. The brand says they adapt to your own oil levels, which in practice means they soak up oil without leaving a chalky film.

What I would skip: a regular dry shampoo on dark hair. Use the brunette one, or you will be rubbing grey dust out of your part all afternoon.

If Nexxus has a signature, it is conditioner. Humectress Ultimate Moisture Conditioner is the white bottle people have been buying for years, a deeply hydrating formula for dry hair made with the brand's caviar and protein complex. If you only try one thing here, try that.

The rest of the grid matches the shampoos. Keraphix Damage Repair Conditioner goes with the purple shampoo, Color Assure Vibrancy Conditioner with the color line, and Hy-Volume Conditioner with the volume line. Clean & Pure Detox Conditioner uses lactic acid and is light enough for oily roots. Ultralight Smooth Conditioner is made with almond protein and white jasmine flower, for frizz without weight.

Keraphix Liquid Crystallizer is a leave-in treatment that the brand says reconstructs bonds from the cuticle to the cortex. You use it on damp hair after washing. The Repair & Nourish Ultra Lightweight Hair Oil is the last step, for shine and to seal in moisture.

A pairing tip: Nexxus is happy to be mixed. Use Keraphix shampoo with Humectress conditioner if your hair is both damaged and dry. The lines are designed as sets, but hair rarely has only one problem.

What I would skip: the oil right at the roots on fine hair. Keep it on the last few inches.

I think Nexxus shampoo makes the most sense if you remember where it came from. Jheri Redding spent his working life arguing that hair is protein and should be treated that way. So pick the shampoo for your problem, pair it with Humectress if your ends are dry, and keep a dry shampoo in your bag for the days in between. Protein first, moisture second, and your hair will tell you when to switch. Humectress alone has earned the brand a lot of loyal fans, and after a week you will see why.