Are products that delay hair regrowth really effective?

It is always frustrating to see hair reappear just a few days after hair removal, which explains the growing interest in hair regrowth‑inhibiting products, whether creams, lotions, serums that inhibit hair regrowth, or oils that inhibit hair regrowth. These treatments, presented as solutions capable of slowing down hair growth, are theoretically based on a modulation of the hair cycle, more specifically on a prolongation of the telogen phase, or resting phase, or a slowing of the anagen phase, which corresponds to the hair growth phase.

Some claims also put forward an effect on the very structure of the hair shaft, in particular via an alteration of keratin synthesis, the main fibrous protein of the hair produced by keratinocytes in the hair follicle, which could lead to finer, less pigmented hairs that may become less visible over successive cycles. Other hypotheses suggest an interaction with signalling pathways involved in the proliferation of matrix cells in the hair bulb, but these mechanisms remain largely speculative.

Despite a booming market for hair regrowth-inhibiting products, scientific data remain limited.

Can wax tree extract slow down hair regrowth?

Frequently cited in anti-regrowth hair treatment formulas, wax tree extract, more precisely the insect wax secreted by Ericerus pela, is in fact far from having demonstrated any inhibitory effect on hair growth. On the contrary, the available scientific data rather suggest a stimulatory effect on the hair follicle. Indeed, certain experimental studies show that the topical application of this wax promotes the transition of the follicle from the telogen phase to the anagen phase. This stimulation is notably accompanied by an increased expression of the growth factor VEGF, thereby improving the supply of nutrients and oxygen necessary for hair growth.

These observations were confirmed by an in vivo study conducted in mice, in which different concentrations of insect wax (30% and 45%) were applied to depilated areas and compared with a positive control consisting of 5% minoxidil, a drug used to treat alopecia. From day 16 onwards, visible hair regrowth was observed in the treated groups, in contrast to the control group. Hair lengths measured in the 30% and 45% groups were significantly greater than those in the control group on days 16 and 20, with performance close to that of minoxidil. Histological analysis showed that this effect did not rely on the formation of new follicles, but on a premature conversion of existing follicles from the telogen phase to the anagen phase, as well as a prolongation of this growth phase. This activity appears to be linked in particular to increased expression of VEGF and to the presence of policosanols in the wax, identified as major active compounds.

Far from slowing down hair regrowth, it would rather appear that wax tree extract actually speeds it up.

Scullcap root to prevent hair regrowth?

Frequently found in products marketed to slow hair regrowth, Scutellaria root in fact appears, in light of current scientific data, to act more as an active ingredient that stimulates hair growth. Different species, notably Nothopanax scutellarium (mangkokan) and Scutellaria alpina, contain flavonoids such as quercetin, which are capable of inhibiting 5α-reductase and thus reducing the production of dihydrotestosterone (DHT), a hormone involved in the miniaturisation of hair follicles. At the same time, these extracts promote the expression of several key growth factors, such as IGF-1, VEGF and KGF, which support the proliferation of hair bulb cells and prolong the anagen phase. Studies conducted on Polyscias scutellaria even suggest effects comparable to those of minoxidil, via mechanisms combining antioxidant activity, reduced inflammation and follicular stimulation. To date, no evidence shows that Scutellaria root can slow hair regrowth.

On the contrary, Scutellaria root appears to promote an environment conducive to their growth, which calls into question its relevance in products marketed as inhibiting hair regrowth.

Tigernut oil, an oil that prevents hair regrowth?

Unlike other ingredients often presented as hair regrowth inhibitors without solid evidence, tiger nut oil, obtained from the tubers of Cyperus rotundus, may be relevant for slowing hair regrowth. Although its mechanism of action is still poorly understood, several hypotheses have been proposed. One of these is based on a possible inhibition of the hair follicle stem cells, which are essential for hair regeneration after epilation. By slowing their activation, the oil could lengthen the intervals between regrowth cycles. Other proposed mechanisms include the induction of apoptosis, the process of programmed cell death, leading to reduced follicular activity.

From a clinical perspective, a study conducted with 91 volunteers presenting undesirable axillary hair yielded particularly noteworthy results. The participants were divided into two groups: 47 applied tiger nut oil twice daily for six months, while 44 used a placebo solution, with both groups continuing regular hair removal every three weeks. One month after the last hair removal session, the evaluation was based on three criteria: hair counting, assessment by an independent observer, and self-assessment by the participants. Very good results were obtained.

Moreover, the independent observer also noted a reduction of more than 60% in hair density in 97.9% of participants who used the tigernut oil, with no improvement in the control group. Finally, a significant reduction in the number of hairs was objectively demonstrated in the group applying the oil.

Although some methodological parameters are not specified, such as the concentration at which tiger nut oil was used, these results suggest that this oil, used to slow hair growth, could represent an interesting avenue, particularly when applied after hair removal.

Lemon juice: a good idea for spacing out hair removal sessions?

Lemon juice is often presented as a home remedy for slowing hair regrowth. However, no robust scientific data support any effect of lemon on the hair growth cycle. Its acidity, due to its high citric acid content (pH around 2), can cause a slight alteration of the stratum corneum and create a feeling of smoother skin or temporarily finer hairs, but this does not reflect any real action on the hair follicle or on the biological mechanisms involved in regrowth.

Moreover, its repeated use on the skin, particularly after hair removal, is not without consequence.

The acidity of lemon can weaken the skin barrier, which is already sensitised, leading to irritation, redness, and even burning sensations. Most importantly, lemon contains furocoumarins, photosensitising compounds that can react with UV radiation and trigger phytophotodermatoses: the appearance of pigmented spots, burns or inflammatory reactions after sun exposure. This risk is particularly high when the juice is applied to recently depilated skin, which is therefore more permeable. Thus, despite its popularity, lemon juice is neither a reliable nor a safe option for slowing hair regrowth, and we advise against applying it to your skin.

Thus, most hair regrowth-inhibiting products rely more on claims than on robust scientific evidence. Only a few approaches, such as tigernut oil, suggest an interesting potential, but they still require further investigation.

• MOHAMMED G. F. Role of Cyperus rotundus oil in decreasing hair growth. Journal of Intercultural Ethnopharmacology (2012).

• ZHANG H. & al. In vivo evaluation of insect wax for hair growth potential. PLOS One (2018).

• MOHAMMED G. F. & al. The potential of Cyperus rotundus L. as a natural hair removal agent: A review of traditional and modern applications. Dermatological Reviews (2025).

• ABU BAKAR F. I. & al. Nothopanax scutellarium: Natural hair growth plant. Jurnal Farmasi Indonesia (2025).