What should I know before switching to this shampoo if my scalp is very reactive?

If your scalp reacts easily to new products, change only one thing at a time. Use this shampoo with your current conditioner (or none) for the first 3–5 washes so you can isolate any response. The formula avoids fragrance — the top cosmetic allergen — and uses calendula for its calming reputation, but individual sensitivity to any plant extract or surfactant is still possible. Before full use, you can do a simple patch test: apply a pea-sized amount behind the ear or on the inner forearm, leave for a few minutes, rinse, and wait 24 hours. No redness or itch means it's likely safe for your scalp. During the first week, wash with lukewarm water, not hot, and massage gently with fingertips — not nails. If stinging, burning, or increased flaking occurs, discontinue immediately. This product is not intended to treat scalp conditions like dermatitis or psoriasis; for diagnosed conditions, consult a dermatologist before switching care routines.