How to maintain healthy hair in autumn?

The sun, sea salt and the chlorine in swimming pools have put hair under severe strain over the summer, weakening its structure. To understand this fully, it is important to recall that each hair fibre comprises a central core, the cortex, which contains the keratin proteins responsible for the fibre's strength and elasticity. This cortex is encased by the cuticle, an outer layer formed of overlapping, flat cells resembling protective scales. However, summer aggressors lift and damage these scales, leaving the cortex more exposed and making hair more susceptible to breakage and split ends. The hair fibres also lose their shine, retain moisture less effectively and display a rougher and porous. This cuticle degradation also makes the hair more prone to frizz and tangles, accentuating the appearance of tired hair at the start of term.

A recent study examined the impact of sunlight on the lipid composition of the hair cuticle to better understand why hair appears drier and duller after summer. The researchers analysed ten blonde hair strands, divided into two groups: one exposed to visible light and UV rays (340 and 420 nm) and the other unexposed. Lipidomic analysis by LC–MS identified 791 distinct lipids out of a total of 3,521 detected signals. The results showed that more than half of the lipid classes were altered by UV exposure, some decreasing sharply, others on the contrary increasing, indicating a disruption of the hair’s lipid barrier during summer.

Accordingly, to maintain optimal hair health in autumn, you should begin by repairing the damage incurred during the summer season.

• Do not omit the conditioner.

  To restore vitality to hair damaged by the summer, one should begin by not overlooking the conditioner. Unlike shampoo, whose purpose is to cleanse the scalp and remove impurities, the conditioner acts directly on the hair fibre. Rich in cationic agents and emollients, this product smooths the cuticles raised by the sun, salt or chlorine, and reduces the electrostatic charge responsible for frizz and tangles. By forming a fine protective film around the hair shaft, it limits water loss and partially restores the hair’s suppleness and shine. In autumn, as in any season, the systematic use of a conditioner, applied to the lengths and ends, is therefore essential.

• Opt for hair masks.

  Hair masks are far from useless and help repair hair damaged by summer. Richer than conditioners, masks typically contain nourishing agents, such as ceramides or plant oils. These compounds reinforce the intercellular cement of the hair fibres, helping restore cuticle cohesion and limit the heightened porosity often observed after sun exposure. Regular application, one to two times a week, replenishes the hair’s lipid and protein reserves while providing protection against mechanical stresses such as brushing.

• Opt for reparative hair serums.

  Repairing hair serums are an effective solution for caring for the ends, which are the first to suffer the consequences of summer damage. Unlike masks, these lightweight treatments typically do not require rinsing but form a protective film around the hair fibre. Hair serums temporarily fill the cuticle’s gaps, thereby limiting breakage and split ends. In addition, their smoothing action enhances light reflection, instantly restoring shine to dull hair. Used daily or several times a week, depending on hair condition, hair serums can be particularly beneficial in autumn.

• Do not hesitate to cut your forks.

  Unfortunately, once split ends appear, the only solution is to trim them off. Moreover, when the cuticle is damaged, the crack advances into the cortex, weakening the entire hair shaft and leading to increased breakage over time. A visit to the hairdresser at the start of the season, even just to remove a few centimetres, enables you to begin on a healthy foundation and preserve the hair’s vitality.

The hair shedding is a natural phenomenon that accompanies the hair follicle’s life cycle, but it becomes particularly pronounced in autumn. This seasonal increase in hair loss can be partly explained by the action of melatonin, a hormone secreted by the pineal gland and inhibited by light exposure. Melatonin plays a key role in the hair cycle by extending the anagen phase, which is the hair’s growth phase. During summer, when sunlight exposure is higher, melatonin production decreases, which accelerates the transition of follicles into the catagen and then telogen phases (rest and shedding). This timing explains why hair shedding is more pronounced in early autumn, several months after peak sun exposure. A clinical study confirmed this effect by showing that a topical application of melatonin to the scalps of women with androgenetic alopecia significantly increased the proportion of hairs in the anagen phase compared with the control group.

• Adopt a balanced, nutrient-rich diet.

  The hair health depends partly on what we put on our plate. Hair, composed mainly of keratin, requires sulphur-containing amino acids for its strength, which are found in eggs, pulses and fish. Minerals such as iron, zinc and silicon also contribute to the growth and vitality of hair fibres, while B-group vitamins promote cellular renewal. In autumn, it is therefore advisable to favour a varied diet incorporating proteins, wholegrain cereals, dried fruits, antioxidant-rich vegetables and sources of omega-3s, such as oily fish or linseeds.

  Note In autumn, dietary supplements designed to stimulate hair growth become increasingly common. While they may seem appealing, we recommend consulting a healthcare professional before beginning any treatment. In the absence of deficiencies, supplementation does not necessarily confer benefits.

• Use fortifying treatments.

  Beyond diet and lifestyle, it can be useful to apply strengthening treatments to the scalp. Certain ingredients, such as caffeine, the rosemary essential oil or even the acetyl tetrapeptide-3, are often incorporated into hair serums or shampoos to prevent hair loss. Caffeine works by stimulating microcirculation and promoting nutrient delivery to the hair follicles, which helps sustain the growth phase. Rosemary essential oil, on the other hand, is thought to inhibit 5α-reductase, the enzyme responsible for converting testosterone into dihydrotestosterone (DHT). In doing so, it prevents DHT from binding to the follicles and disrupting their growth cycle. Finally, acetyl tetrapeptide-3 is a biomimetic peptide that acts on the follicular environment by supporting the extracellular matrix, which promotes better anchorage of the fibre within its bulb.

Most haircare routines centre on the lengths and tend to leave the scalp in the background. Yet it serves as the foundation of the hair : this is where hair follicles originate, and their activity directly determines hair quality, density and vitality. An imbalanced scalp – whether too dry, irritated or, conversely, oily – can weaken the fibre right from its formation. In autumn, when hair undergoes a more pronounced seasonal shedding, caring for this area is essential to foster an environment conducive to healthy regrowth.

• Use an appropriate shampoo.

  The choice of shampoo is often guided by the condition of the hair lengths, whereas it should first meet the needs of the scalp. An oily scalp, for example, requires rebalancing formulations that curb excessive sebum production without irritating the skin. Conversely, a dry or irritation-prone scalp will benefit more from gentle, hydrating treatments enriched with soothing agents such as aloe vera or glycerine.

  Dandruff flakes are another common issue that warrants particular attention. They generally arise from an excessive proliferation of Malassezia, a yeast naturally present on the scalp that leads to accelerated scaling. In this case, an anti-dandruff shampoo formulated with antifungal agents such as zinc pyrithione or piroctone olamine can help to restore the balance of the skin microbiota and soothe itching. For dry flakes, which present as small white particles with associated dryness, it is preferable to use moisturising and nourishing formulations. Conversely, greasy flakes, which are thicker and have a yellowish hue, are often accompanied by excess sebum and require suitably purifying shampoos.

• Regularly exfoliate your scalp.

  In autumn, to renew the scalp after summer, it is beneficial to begin using a scalp scrub. Like facial or body scrubs, the purpose of this treatment is to remove accumulated impurities and help unclog follicles. This exfoliation also stimulates microcirculation, thus enhancing oxygenation of the hair roots and promoting improved growth. Performed once or twice a week, especially during the autumnal transition when hair shedding increases, it helps maintain a healthy scalp that is receptive to subsequent treatments.

• EBLING F. & al. Seasonal changes in human hair growth. British Journal of Dermatology (1991).

• FISCHER T. W. & al. Melatonin increases anagen hair rate in women with androgenetic alopecia or diffuse alopecia: Results of a pilot randomized controlled trial. British Journal of Dermatology (2004).

• TRÜEB R. & al. Seasonality of hair shedding in healthy women complaining of hair loss. Dermatology (2009).

• SAHEBKAR A. & al. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed (2015).

• KLENK A. & al. Caffeine and its pharmacological benefits in the management of androgenetic alopecia: A review. Skin Pharmacology and Physiology Journal (2020).

• PANCHAPRATEEP R. & al. An herbal extract combination (biochanin A, acetyl tetrapeptide-3, and ginseng extracts) versus 3% minoxidil solution for the treatment of androgenetic alopecia: A 24-week, prospective, randomized, triple-blind, controlled trial. The Journal of Clinical and Aesthetic Dermatology (2020

• WILLICUT R. J. & al. UV and visible light exposure to hair leads to widespread changes in the hair lipidome. International Journal of Cosmetic Science (2022).