Dry shampoo and hair loss: build-up, benzene recalls and sensible use

Dry shampoo has become a regular part of many people's routines in Malaysia. It is quick, it rescues hair after the gym or a long day under a helmet or tudung, and it can make fine hair look fuller. At the same time, it has picked up a worrying reputation online: posts claim it clogs follicles and causes hair loss, and news of benzene recalls in 2021 and 2022 made many people wonder whether their can was safe. This article looks at what dry shampoo actually does, what dermatologists say about build-up and shedding, what the benzene recalls involved, and how to use dry shampoo sensibly.

(This is general information, not personal medical advice.)

Short answer

Dry shampoo absorbs oil but does not clean the scalp, and dermatologists advise that it should not replace washing with shampoo and water ¹. There is no good evidence that occasional use causes pattern hair loss. However, the American Academy of Dermatology notes that dry shampoo left on the hair or scalp can lead to problems such as breakage and shedding, and that relying only on dry shampoo without washing could lead to seborrhoeic dermatitis, an itchy, scaly scalp rash ¹. In December 2021 and October 2022, two large manufacturers voluntarily recalled certain aerosol dry shampoos in the United States after benzene was detected, a chemical classified as a human carcinogen; both companies stated that the levels found would not be expected to cause adverse health consequences and recalled the products out of caution ², ³. A sensible approach is to use a small amount at the roots, brush it out, and wash with regular shampoo after one or two uses ¹. If you are shedding a lot, look for the cause rather than blaming one product.

What dry shampoo is, and what it is not

Dry shampoo contains small particles that absorb oil, so greasy roots look and feel fresher. Common absorbent ingredients include starches and other powders, and many products are sold as aerosols with a propellant, while others are loose powders.

Dermatologists quoted by the American Academy of Dermatology are clear on one point: dry shampoo does not clean hair. It absorbs oil, but only regular shampoo and water remove dead skin cells, oil, microorganisms and the dry shampoo itself from the scalp ¹. Dry shampoo is best thought of as a way to stretch the time between washes, not a substitute for washing.

Dermatologists also mention practical uses: making salon styles or colour last longer, giving fine hair a fuller look, and, in tinted versions, covering grey roots ¹.

Does dry shampoo cause hair loss?

Pattern hair loss and alopecia

Pattern hair loss is driven by genetics and hormones, and alopecia areata is an autoimmune condition. There is no good evidence that occasional dry shampoo use causes either of them. If you are noticing a widening part, a receding hairline or patches, the cause is likely to be elsewhere; see Hair loss treatment in Malaysia: a plain guide to your options.

Build-up, breakage and shedding

Build-up is the more realistic concern. The American Academy of Dermatology notes that if dry shampoo stays on the hair or scalp, it can cause problems such as hair breakage and hair shedding ¹. Using too much can make hair dry, stiff and gritty, leave visible particles, and irritate the scalp ¹. Homemade dry shampoos can clump and clog pores, which may make the scalp itch, burn or feel tender ¹.

Breakage is different from hair falling out from the root. Broken hairs are short pieces without a root bulb, while hairs shed from the root are usually longer, with a small white bulb at one end. See Hair breakage vs hair loss: how to tell.

Skipping washes and the scalp

The AAD also reports that using only dry shampoo and skipping washes could contribute to seborrhoeic dermatitis, which causes an itchy, scaly rash on the scalp ¹. Seborrhoeic dermatitis and dandruff are linked to sebum, skin yeast called Malassezia and individual susceptibility ⁴. Regular washing helps remove the oil and skin cells that this yeast feeds on.

How often to wash is personal, but one study offers some perspective for Asian populations. In two studies of Asian adults without scalp conditions, overall satisfaction with hair and scalp was highest among people washing five to six times a week, and a daily wash routine performed better than washing once a week on all measures, with no objective harm to hair at that frequency ⁵. The study was funded by a shampoo manufacturer, so it is best read as one data point. See How often should you wash your hair?.

The benzene recalls: what happened

December 2021

In December 2021, Procter & Gamble voluntarily recalled aerosol dry shampoo and dry conditioner spray products from brands including Pantene, Aussie, Herbal Essences and Waterless produced in the United States, after benzene was detected in some products ². The company stated that benzene is classified as a human carcinogen and that exposure can occur through inhalation, by mouth or through the skin. Based on exposure modelling, it stated that daily exposure to benzene at the levels detected would not be expected to cause adverse health consequences, that it had received no reports of adverse events, and that the recall was out of an abundance of caution ².

The recall reached Malaysia. According to a December 2021 news report, P&G recalled one Pantene aerosol dry shampoo product in Singapore and Malaysia as part of the global recall of the version produced in the United States, and stated that benzene was not an ingredient but low levels had been detected ⁶.

October 2022

In October 2022, Unilever voluntarily recalled select lots of aerosol dry shampoos produced before October 2021 from Dove, Nexxus, Suave, TIGI (Rockaholic and Bed Head) and TRESemmé in the United States because of potentially elevated levels of benzene ³. An internal investigation identified the propellant as the source. As with the earlier recall, the company stated that, based on an independent health hazard evaluation, daily exposure at the levels detected would not be expected to cause adverse health consequences, and that it had received no reports of adverse events ³.

What this means for you

The recalls concerned specific products and batches, and benzene was a contaminant rather than an ingredient. They are not evidence that dry shampoo in general causes hair loss, and the companies' own assessments did not expect health effects at the levels found. They do show why it is worth:

• checking whether an older can you still own was part of a recall
• buying from established sellers rather than unknown sources
• considering a non-aerosol powder if you prefer to avoid propellants
• spraying in a ventilated space and not inhaling the mist

How to use dry shampoo sensibly

Advice from dermatologists quoted by the American Academy of Dermatology includes ¹:

1. Use store-bought dry shampoo rather than a homemade one. Homemade versions made from cornstarch, cocoa powder or baking soda can clump and clog pores, and bacteria can digest cornstarch, which can cause an unpleasant odour.
2. Choose a product for your hair type and colour. If your hair or scalp feels parched afterwards, try a fragrance-free version.
3. Apply a small amount only where needed, starting at the scalp, and add more only if hair still feels greasy.
4. Leave it for the time on the label, then brush or comb it out. Brushing removes the oil along with the powder.
5. Wash with regular shampoo and water after one or two uses of dry shampoo.
6. Stop if you develop itching, burning or irritation. If irritation does not improve within a few weeks, see a dermatologist.

Fragrance is a commonly reported allergen in scalp contact dermatitis, so a fragrance-free product may suit a sensitive scalp better ⁷.

Dry shampoo in a hot, humid climate

Sweat and humidity can make roots look oily within hours, and many people reach for dry shampoo between washes. In Malaysia's climate, the practical points are:

• Dry shampoo cannot remove sweat, salt and skin cells. After heavy sweating, rinsing or washing is more useful. See Does sweat cause hair loss? Gym, heat and your scalp.
• Women who wear a tudung may wash less often because of the time it takes to dry hair. Dry shampoo can help between washes, but a breathable scarf and properly dried hair matter too. See Hijab and hair loss: practical scalp care for women who cover.
• A smelly or itchy scalp often improves with a more regular washing routine rather than more dry shampoo. See Smelly scalp: why it happens in a humid climate and how to fix the routine.

Signs your dry shampoo routine needs a change

Dry shampoo works best as an occasional helper. It may be time to adjust your routine if:

• your scalp feels itchy, tight or tender on days you use it
• you see white or grey particles at the roots or on your shoulders
• your hair feels stiff, gritty or dull, or tangles more easily
• you notice flakes or an unpleasant smell between washes
• you find you are using it most days instead of washing

A simple adjustment is to go back to washing with regular shampoo more often, use dry shampoo only on the day or two in between, and use less of it each time. If you have an oily scalp, a shampoo suited to oily hair, used regularly, often controls greasiness better than adding more powder. If you have dandruff, an anti-dandruff shampoo addresses the cause on the scalp, which dry shampoo cannot do. See Oily scalp and hair loss: is oil to blame? and Stubborn dandruff that keeps coming back: why it happens in Malaysia and what helps.

Keep track of changes for two to four weeks after adjusting your routine. If itching and flaking settle, build-up was probably part of the problem. If they do not, a doctor can check for seborrhoeic dermatitis, contact dermatitis or another scalp condition.

When shedding is not about dry shampoo

If you are shedding more than usual, dry shampoo is rarely the main cause. Common causes of hair loss include pattern hair loss, telogen effluvium after illness, stress, childbirth or weight loss, thyroid disease, iron deficiency, medicines and scalp conditions ⁸. Excessive shedding that starts a few months after a stressful event, illness, high fever or childbirth is often temporary ⁹.

See a doctor if you notice:

• sudden or heavy shedding
• round bald patches
• a red, painful, scaly or weeping scalp
• itching or burning that continues after stopping dry shampoo
• hair loss with other symptoms such as tiredness or weight change

Useful questions to ask include whether your scalp shows signs of seborrhoeic dermatitis or contact dermatitis, whether tests for iron or thyroid levels are needed, and what type of hair loss you have.

Life in Malaysia

Dry shampoo is widely available in Malaysian pharmacies, supermarkets and online, including imported brands. For imported products bought online, check that the seller is reliable and that the product has a clear label. In Malaysia, cosmetics such as dry shampoo must be notified to the National Pharmaceutical Regulatory Agency before they are manufactured, imported or sold ¹⁰. If you want a scalp or hair loss assessment, choose a registered doctor; registration can be checked with the Malaysian Medical Council ¹¹. For more on shampoo choices, see Hair loss shampoo: what a shampoo can and cannot do and Sulfate-free and silicone-free shampoo: do they matter for hair fall?.

Bottom line

Dry shampoo absorbs oil but does not clean the scalp. Used now and then, there is no good evidence that it causes pattern hair loss, but leaving it to build up can contribute to breakage, shedding and an irritated or flaky scalp. The 2021 and 2022 benzene recalls involved specific aerosol products, and the companies stated the levels found would not be expected to cause health effects; they are a reason to check older cans and buy from reliable sellers, not to fear every bottle. Use a small amount at the roots, brush it out, wash after one or two uses, and stop if your scalp itches or burns. If shedding is heavy, find the cause.

Frequently asked questions

Does dry shampoo cause hair loss?

There is no good evidence that occasional use causes pattern hair loss. Dermatologists note that dry shampoo left to build up on the hair or scalp can contribute to breakage and shedding.

Does dry shampoo clean your hair?

No. It absorbs oil but does not clean. Only shampoo and water remove dead skin cells, oil, microorganisms and the dry shampoo itself.

How often can I use dry shampoo?

There is no fixed number, but dermatologists quoted by the American Academy of Dermatology suggest washing with regular shampoo after one or two dry shampoo uses.

Can dry shampoo cause dandruff or seborrhoeic dermatitis?

Relying only on dry shampoo and skipping washes could contribute to seborrhoeic dermatitis, an itchy, scaly scalp rash, according to the AAD.

Is dry shampoo safe after the benzene recalls?

The 2021 and 2022 recalls involved specific aerosol products and batches; the companies stated the levels detected would not be expected to cause adverse health consequences. Check older cans and buy from reliable sellers.

Was any recalled dry shampoo sold in Malaysia?

A December 2021 news report said P&G recalled one Pantene aerosol dry shampoo in Singapore and Malaysia as part of its global recall.

Is homemade dry shampoo better?

Dermatologists advise store-bought products. Homemade versions made from cornstarch or baking soda can clump and clog pores, and cornstarch can lead to an unpleasant odour.

What should I do if my scalp itches after dry shampoo?

Stop using it. If irritation does not improve within a few weeks, see a dermatologist to check for contact dermatitis or another scalp condition.

Educational content. Not medical advice.