Sources

Every number in the guides and the planner comes from one of these, or is labelled approximate.

Published sources

• Henna Sooq: How Much Henna and Ayurvedic Herbs to Use on Your Hair?. Grams per application by hair length (above ear 50-75 g, shoulder 100-125 g, bra strap 150-175 g, lower back 200-225 g, hip/waist 250-300 g); amla 1-2 tbsp per 100 g of henna or indigo.
• Henna Sooq: Indigo Powder for Hair: Brown to Black Color Guide. One-step ratios (reddish brown 70/30, brown 50/50, dark brown about 1:3, dark chocolate 30/70 henna/indigo); black = two-step, indigo within 72 hours of henna; indigo rests 20-30 minutes; colour develops over 24-48 hours; never use indigo alone.
• Henna Sooq: Color Your Hair Brown to Black: How to Mix Indigo for Hair. Mix indigo with warm water only to a thick yogurt consistency; rest 20-30 minutes; henna and indigo treatments last about 4-6 weeks before roots show.
• Henna Sooq: How Long Should You Let Henna Sit for Dye Release? 24 Hours?. Dye release for their henna is about 3-4 hours; henna has a peak and loses potency after it. Other suppliers suggest overnight, so the planner shows the full 3-12 hour range and says to follow your powder.
• U.S. Food and Drug Administration: Temporary Tattoos, Henna/Mehndi, and "Black Henna": Fact Sheet. Henna is approved only as a hair dye, not for direct application to skin; "black henna" may contain PPD and has caused skin injuries.
• Product labels and instructions. The instructions on your henna, indigo, oil or hydrosol, and general cosmetic practice. When they differ from a guide, follow them.

Timings that come from common practice, not one sheet

These ranges recur across supplier and maker instructions but no single listed source gives them, so the guides and the planner present them as approximate: henna on hair for about 2-4 hours (little gain past about 4 hours); henna colour deepening over about 24-72 hours after rinsing; an overnight henna dye release of about 8-12 hours for powders whose instructions call for it (Henna Sooq gives about 3-4 hours for its own blend). Your powder's own instructions come first.

Planner approximations

Rounded starting points where no supplier sheet gives a number: chin-length grams (between the above-ear and shoulder rows), the fine/thick multipliers, the cassia blend for golden tones, indigo and cassia leave-on times, and the swatch colours. Each is labelled approximate on the page.

Swatch colours on the strand card are drawn to show the direction of change (bright on day 0, deeper by day 3). They are not measured colours.

Retrieved

Sources were read on 3 November 2026. Supplier pages change; if a link has moved, let us know.