COSMTEK Dark Brown Hair Dye Shampoo 500ml — 3‑in‑1 Color‑Depositing, Sulfate‑Free Conditioning Formula

COSMTEK Dark Brown Hair Dye Shampoo is a 3-in-1 color-depositing shampoo that instantly darkens gray and light hair while cleansing and conditioning for up to 4–5 weeks.

This 500ml formula blends pigments with conditioning oils so you can refresh or change your shade during routine washing. Designed for use on damp hair, the product deposits rich dark brown color in 15–20 minutes while smoothing frizz and adding shine. The updated formula is free of sulfates, ammonia, and added preservatives, and it includes argan oil, olive oil and turmeric to help keep hair soft and manageable after coloring.

How quickly will I see color results?

Most users notice a visible darkening after a single 15–20 minute application on wet hair. Results vary by starting hair shade and porosity; lighter or gray hair accepts pigment faster, while very thick hair may need extra processing time.

• Apply to wet hair like a regular shampoo for even distribution.
• Leave on 15–20 minutes; 1–2 extra minutes may help very thick hair.
• Rinse thoroughly until water runs clear to avoid patchiness.

Will this damage or dry out my hair?

The COSMTEK formula was upgraded to exclude sulfates, ammonia and common preservatives, and it includes moisturizing oils to reduce frizz and dryness. It conditions while depositing color, so hair feels softer than many permanent dyes.

• Argan oil and olive oil add hydration and shine.
• Turmeric supports smooth, manageable texture without harsh chemicals.
• Suitable for color-treated hair as a refresh between salon visits.

How long does the color last and how often should I use it?

Expect the dark brown tint to hold for about 4–5 weeks after an application; fading depends on hair washing frequency and products used. For continuous color and shine, reapply roughly every 15 days or as needed to maintain depth.

• Single application provides up to 4–5 weeks of tone retention.
• Reapply every ~15 days to preserve saturation and gloss.
• Use color-safe or sulfate-free shampoos to extend wear.

How do I use it safely and get the best coverage?

Perform an allergy patch test 24 hours before full use by applying a small amount behind the ear. Use the shampoo on damp hair, choose amounts based on hair volume, and leave it on the recommended time for even coverage.

• Do an allergy test behind the ear and wait 24 hours.
• Apply to wet hair and massage from roots to ends for uniform color.
• Adjust quantity and processing time for very thick or coarse hair.

Who is this for: COSMTEK Dark Brown Hair Dye Shampoo is made for men and women who want an easy at-home color refresh that combines cleansing and conditioning in one step. It suits people with gray, light brown, or previously colored hair looking for a natural dark brown shade without harsh dyes. Ideal for busy routines, those avoiding ammonia and sulfates, and anyone wanting temporary-to-semi-permanent color that washes down over weeks rather than lasting permanently.