“40 volume” is how hair developers are labeled in the color world. It refers to the oxidizing strength, or how much oxygen the product can release to help hair color or lightener work.

• Strength: 40 volume developer is typically 12% hydrogen peroxide (not 40%).
• What it does: It’s the strongest commonly used cosmetic developer, chosen when significant lightening or high-lift color is desired.
• How it’s used: It’s mixed with permanent hair color or powder lightener per the product’s directions.

Always follow the mixing ratios and timing on the specific product’s label, and consider strand and patch tests to preview results. Individual hair condition and history can affect outcomes.

They’re not the same. In hair color, “40 volume” is a category name for developer strength and typically equals 12% hydrogen peroxide.

• 40 volume: Cosmetic-grade developer used with hair color or lightener; usually around 12% H2O2.
• 40% peroxide: A much higher concentration that isn’t the same as 40 volume and isn’t intended for cosmetic use.

For hair coloring, look for developers labeled by volume (10, 20, 30, 40) and always check the product’s percentage on the label. Use as directed by the manufacturer, since mixing ratios and processing times vary by formula and desired result.

40 volume developer is often chosen when you’re aiming for more dramatic lightening or working with high-lift color formulas.

• Common uses: Significant blonding, lifting dark or resistant hair, or powering lighteners formulated for higher lift.
• What to consider: Hair health, previous color services, and scalp sensitivity can impact whether 40 volume is appropriate.
• Good practice: Do a strand test, follow the brand’s mixing ratio and timing precisely, and avoid overlapping on previously lightened hair.

If you’re unsure, consider starting with a lower volume or consulting a licensed colorist. Results can vary based on hair condition, application technique, and product choice.

You’re in the right spot. This page features a range of 40 volume cream peroxide developers in different sizes and formats.

• How to shop: Browse the listings, open product pages to see the percentage (typically 12%), formula type (cream or liquid), and usage instructions.
• Fulfillment: Choose from shipping, pickup, or delivery where available in your area.
• Helpful tips: Check item details for mixing ratios, read customer reviews, and confirm it’s compatible with your chosen hair color or lightener.

Add to cart when you’re ready and follow the manufacturer’s directions for safe mixing, application, and timing.

40 volume is strong, so a careful approach helps. While results vary by hair type and history, these guidelines can support safer use:

• Prep: Read the product’s directions end-to-end, perform a patch test and a strand test.
• Tools: Use non-metal bowls and tools; wear gloves and protect clothing/skin.
• Application: Mix only as directed and apply in a well-ventilated area. Avoid contact with eyes, eyebrows, and eyelashes.
• Timing: Follow the manufacturer’s recommended processing time—don’t exceed it.
• Aftercare: Rinse thoroughly and condition. Store the developer tightly closed, away from heat and sunlight, and out of reach of children and pets.