Ingredient review
Lawsone
INCI: LAWSONE
Lawsone is a natural colorant from henna that stains hair and skin, but it can cause irritation in sensitive individuals and is not approved for use in leave-on cosmetics in some regions.
In plain English
Lawsone is the pigment in henna that gives hair and skin a reddish-brown stain. It works by binding to proteins in the outer layer of skin or hair, creating a semi-permanent color. While natural, it can be drying and may cause allergic reactions in some people. It is not the same as 'black henna,' which often contains harmful additives.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- natural
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Lawsone can be useful, but watch for some irritation potential.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Lawsone.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Lawsone (2-hydroxy-1,4-naphthoquinone) is a naturally occurring organic compound found in the leaves of the henna plant (Lawsonia inermis). It is the primary coloring agent responsible for henna's staining properties.
How it works
Lawsone molecules bind to keratin proteins in the outer layer of skin and hair, forming a stable, colored complex. This staining is semi-permanent and fades as the skin sheds or hair grows out. The color develops over several hours and is influenced by the pH and temperature of the application.
Pros
Natural origin
Derived from henna leaves, lawsone is a plant-based colorant that appeals to those seeking natural beauty alternatives.
Semi-permanent color
The stain lasts for several days on skin and weeks on hair, fading gradually without harsh regrowth lines.
Cons and cautions
Potential irritation
Lawsone can cause allergic reactions or contact dermatitis, especially in individuals with sensitive skin or existing allergies.
Regulatory restrictions
In the European Union, lawsone is not approved for use in leave-on cosmetic products due to safety concerns, limiting its availability in some markets.
Best for
- People seeking a natural-looking reddish tint for hair or skin
- Those who prefer plant-derived colorants over synthetic ones
Use caution if
- Individuals with known allergies to henna or p-phenylenediamine (PPD)
- Those with sensitive or damaged skin or scalp
Usage tips
Safety summary
Lawsone is generally safe for most people when used in rinse-off products, but it carries a moderate risk of skin irritation and allergic reactions. It is not recommended for leave-on applications due to sensitization potential.
Research notes
Studies confirm lawsone's ability to bind to keratin and produce stable color. However, research also indicates it can cause contact dermatitis in susceptible individuals, leading to regulatory restrictions in some regions.
Common label clues
- Typical concentration
- 0.1% to 5% in rinse-off products; higher in leave-on colorants
- Regulatory status
- Approved for use in rinse-off hair dyes in many countries, but restricted or banned in leave-on cosmetics in the EU and some other regions due to sensitization concerns.
- Common uses
- Hair dyes, Temporary tattoos, Nail stains
- Environmental note
- Henna is a sustainable crop that requires minimal water and pesticides, making lawsone a relatively eco-friendly colorant compared to synthetic alternatives.
Good to know
- Lawsone is not the same as 'black henna,' which often contains PPD and can cause severe skin reactions.
- The color from lawsone is permanent on hair until it grows out or is cut, but it fades gradually on skin.
Common questions
What is Lawsone in beauty products?
Lawsone is the pigment in henna that gives hair and skin a reddish-brown stain. It works by binding to proteins in the outer layer of skin or hair, creating a semi-permanent color. While natural, it can be drying and may cause allergic reactions in some people. It is not the same as 'black henna,' which often contains harmful additives.
What does Lawsone do in a beauty product?
Lawsone molecules bind to keratin proteins in the outer layer of skin and hair, forming a stable, colored complex. This staining is semi-permanent and fades as the skin sheds or hair grows out. The color develops over several hours and is influenced by the pH and temperature of the application.
Is Lawsone safe for most people?
Lawsone is generally safe for most people when used in rinse-off products, but it carries a moderate risk of skin irritation and allergic reactions. It is not recommended for leave-on applications due to sensitization potential.
Who should be careful with Lawsone?
Individuals with known allergies to henna or p-phenylenediamine (PPD) Those with sensitive or damaged skin or scalp
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.