Pourquoi mes cheveux do they grow back curly?

Discovering that your hair is growing back curly when it was straight – or the opposite – surprises and destabilizes many people after chemotherapy. This phenomenon has a name: “chemo curls”. It is common and does not indicate anything abnormal.

The changes observed are varied: hair that is more curly or wavy, finer, drier, or of a changed color — sometimes darker, sometimes graying. These modifications can coexist. They concern the new regrowth, that which emerges after the end of the treatment.

To understand curl, you have to look closely at the hair follicle, the small structure that makes hair. The shape of the hair — straight, wavy or curly — depends largely on the shape of the follicle and how the shaft is constructed at its base.

The matrix, at the origin of the shape of the hair

At the base of the follicle, the matrix contains the cells that divide to make the hair shaft. The geometry of this production determines whether the hair will be straight or curly. Chemotherapy, by temporarily disrupting these rapidly dividing cells, can modify the shape of the stem produced during regrowth: this is the main explanation for “chemo curls”.

Le canal de sortie et la gaine conjonctive

The hair, once formed, travels towards the surface through a canal surrounded by sheaths, including the connective sheath which envelops the follicle. The shape and state of this channel help guide the exit of the hair. When the scalp has been weakened, an alteration of this environment can contribute to modifying the axis and shape of the shaft at its exit. This factor is plausible and consistent with what we observe, even if the exact part it plays, in relation to the disturbance of the matrix, remains debated.

Beyond the follicle itself, the general condition of the scalp after chemotherapy influences the conditions for regrowth. A weakened scalp — inflammatory, with impaired barrier function, disrupted microcirculation — offers an environment less conducive to regular regrowth.

Dermatological disturbances of the scalp can thus accompany, or even accentuate, irregularities in regrowth, including the shape of the hair when it emerges. Restoring healthy ground does not mechanically “correct” the curl, but creates better conditions for quality regrowth, as the follicle recovers.

Since the condition of the scalp contributes to the conditions for regrowth, taking care of it is part of the support. This is the logic of the RENASCOR Laboratory: we rebuild before stimulating, that is to say, restoring the land before supporting growth.

REDACTIV 1 serum, an early reconstruction treatment of 99% natural origin, is formulated to act in this area: soothe perifollicular inflammation, support the barrier function of the scalp and restore a more favorable follicular environment. By improving these conditions, it supports the regrowth phase - without constituting a treatment for frizz or guaranteeing the return to the original texture, which depends on the natural recovery of the follicle. Discover REDACTIV 1.

This is the most reassuring question: chemo curls are, in the vast majority of cases, temporary. As the follicle returns to normal function, the original texture tends to return.

The return occurs gradually, generally over several months to one to two years, over the course of regrowth cycles. The first regrowths most often bear the mark of “chemo curls”; the hair produced then gradually regains its initial character. Patience and scalp care accompany this transition.