WikiCompare live prices on shampoo across Amazon, eBay, Walmart, Target, Best Buy, AliExpress, and curated Awin partner merchants. Match shampoo to scalp type, not hair type. Oily scalp: clarifying shampoo (Olaplex No. 4C, Ouai Detox) used once weekly. Dry/dandruff: Nizoral A-D (ketoconazole) — actual medication, works after weeks not days. Color-treated: sulfate-free (Pureology Hydrate, Olaplex No. 4). Volume: Bumble & Bumble Thickening. Curly: Devacurl No-Poo or Curlsmith. Stop using shampoo daily — 2-3 times per week is enough for most adults; over-washing dries the scalp and triggers more oil production. Always condition mid-shafts to ends, never the scalp. Click any card to open the seller's product page; we earn a small affiliate commission at no extra cost to you.
Frequently asked questions about shampoo
How often should I wash my hair?
2-3 times per week for most adults — daily washing strips natural oils and triggers more oil production (creating a wash cycle dependency). Curly and dry hair types: 1-2 times per week. Fine/oily hair: every other day. Dry shampoo (Batiste, Klorane) extends time between washes. Most people who 'have to wash daily' just need to retrain their scalp over 2-3 weeks.
Sulfate-free vs regular shampoo — which is better?
Sulfate-free (Pureology, Olaplex No. 4, Devacurl) for: color-treated hair (sulfates strip dye), curly/wavy hair, dry hair, sensitive scalps. Regular sulfate shampoo (cheaper, lathers more) for: oily scalps, daily heavy-styling-product use, fine hair that gets weighed down. Modern sulfate-free formulas lather better than they used to.
What's the best shampoo for dandruff?
Nizoral A-D (ketoconazole 1%, OTC) is the strongest dandruff treatment — use 2x weekly, leave in scalp 5 minutes before rinsing. Head & Shoulders Clinical Strength as backup. Selsun Blue (selenium sulfide) for stubborn cases. Use medicated shampoo as a treatment, alternate with regular gentle shampoo — daily medicated use can over-dry the scalp.
Is salon shampoo really better than drugstore?
Sometimes — but the price gap usually exceeds the quality gap. Salon (Pureology, Kerastase, Olaplex): better for color-treated/damaged hair, smoother feel, salt-free formulas. Drugstore (L'Oreal Elvive, Dove, Tresemmé): improved dramatically in last decade, beats salon options at one-quarter the price for most hair types. Try drugstore first; upgrade only if you see specific issues.
Do I need conditioner every time I shampoo?
Almost always yes — shampoo opens hair cuticles, conditioner seals them back down. Skipping conditioner causes static, tangles, and split ends. Exceptions: oily scalps may skip conditioner at the roots (apply only mid-lengths to ends). Co-washing (conditioner-only washing, for curly hair) works for some hair types but not all.
How do I stop hair from thinning?
First, see a doctor — thinning can signal thyroid, iron deficiency, hormones, or genetics. OTC treatments with evidence: minoxidil (Rogaine, 2% for women, 5% for men) — works but must be used continuously. Nutrafol and Viviscal (supplements) — modest evidence. Hair-thickening shampoos (Pureology Strength Cure) help appearance but don't grow new hair.