Aloe has been in the medical books for a very long time. It turns up in the first century CE in the materia medica attributed to Dioscorides, the Greek physician who catalogued the plants used in Mediterranean medicine, and the American Herbal Products Association notes that the aloe chapter may be a later addition. So the attribution is a little shaky, but the plant itself has been a fixture of healing for two thousand years. A bottle of aloe on a bathroom shelf is about as old a habit as a habit gets.

Biolage is built on a newer version of the same instinct. It launched in 1990, and the brand says it was born from the wish to combine bio-science with nature, offering salons professional haircare along with spa treatments such as head massages and uplifting fragrance. It belongs to Matrix, which Arnold and Sydell Miller founded in Cleveland in 1980 and which L'Oréal's Cosmair acquired in 2000. What I like is the point of view: a shampoo is a small ritual, not a chore. Today the brand says each collection has a concentrate with two key ingredients, one scientific and one natural.

The trick is to choose by what your hair is doing this month. Hydra Source Shampoo for Dry Hair and Ultra Hydra Source Conditioner for Very Dry Hair are the moisture pair, with the second meant for the driest lengths. Strength Recovery Shampoo and Conditioner are for hair that has been bleached, heated or both. Color Last Shampoo is for colour-treated hair, Scalp Sync Clarifying Shampoo is for an oily scalp, and Smooth Proof Shampoo is for frizz, the one I would put in a humid-weather drawer.

Most people skip the mask, and it is the step that does the most for dry hair. A deep treatment left on for the full time beats a third wash in a week.

Ultra Hydra Source Deep Treatment Mask for Very Dry Hair is the richer of the two hydrating options, and Strength Recovery Deep Treatment Mask is the one for damage. Use them once a week, swapping with your conditioner, and do not leave either on beyond the directions. After the shower, Hydra Source Leave-In Cream for Dry Hair is the one I would use on ends, and the Hydra Source Daily Leave-In Tonic is the lighter sprayable version for days when a cream feels like too much. Strength Recovery Repairing Spray is the same idea for damaged hair.

For finishing, Smooth Proof Hair Serum works on frizz, the Styling Gelée is the hold for when you want your waves to stay put, and the All-In-One Multi-Benefit Styling Oil is for a little shine at the end.

A pairing I like: the leave-in cream on damp hair, the serum on dry ends after styling. Two small layers behave better than one big one.

What I would skip: a mask on hair you washed with a clarifying shampoo that same night, unless you are prepared to leave it on properly. Sort the scalp first, then feed the lengths.

A conditioner can feel wonderful on day one and leave fine hair flat by day ten. So I rinse one thoroughly and give the same bottle two weeks before deciding.

Redken's Acidic Bonding Concentrate Conditioner is the one for bleached hair that has lost its give, and the Acidic Grow Full System Densifying Conditioner is the choice for thinner-feeling hair. Matrix, the company that owns Biolage, has two here: Food For Soft Hydrating Conditioner for dry and brittle hair, and Instacure Build-A-Bond Mighty Care Conditioner for very damaged hair. Pureology's Hydrate Conditioner is for dryness, and Strength Cure is for damage and split ends.

Olaplex No.5 Bond Maintenance is the everyday conditioner in the bond-care family, and No.5L Moisturize & Mend Leave-In Conditioner for Split Ends is the leave-in you would use on the lengths after.

I like a moisture shampoo from Hydra Source with a bond conditioner from this grid once a week. It gives dry hair the water and damaged hair the repair.

What I would skip: switching to a heavy conditioner the week before a humid holiday. Test new bottles at home first.

Your scalp is skin, and it likes the same logic as your face. A pre-shampoo scrub once a week, a leave-on treatment for whatever it needs, and nothing too heavy in between.

Moroccanoil Purifying Pre-Wash Scalp Scrub and Dr. Groot Pre-Shampoo Exfoliating Detox Water for Scalp Build Up are the two I would put before a wash. Mizani's Wonder Crown Clarifying Scalp Treatment is the clarifying option. Oribe's Serene Scalp Oil Control Treatment Mist is for a scalp that gets oily by afternoon, and the Serene Scalp Soothing Leave-On Hair Treatment is for a flaky one. For thinning, UNITE Hair BOOSTA PLUS+ Scalp Serum and indē wild Moonlight Growth Scalp Serum are the two serums here, and Dr. Groot's Scalp Barrier Boost Oil in Serum is the leave-in treatment.

The scrub sits well before a lightweight shampoo such as Scalp Sync from the first grid. The whole ritual takes two more minutes, and I find it the easiest one to keep, because it lives in the shower you were already taking. Dr. Groot's Detox Water in particular is quick enough to do on a weekday.

What I would skip: scrubbing a scalp that is already irritated or flaky in a painful way. Check with a dermatologist first.

The way I see it, you choose Biolage one problem at a time. Pick Hydra Source if you are dry, Strength Recovery if you have damage, and leave the scalp treatments until the lengths are happy.

Buy the shampoo and conditioner, add the mask once a week, and give it a full month before you judge it. Take a photo of your ends on day one so you have something honest to compare against, and stay with the same routine long enough to see it through.

A little aloe, a small ritual, and two thousand years of people being right about it. If you want to keep browsing, I also put together L'Oréal Ever Pure Shampoo, the 2009 Sulfate-Free Color Line and Redken Shampoo.