Hair Colouring: Does Castor Oil Fade Colour?

Whether it's for a change of look or to conceal grey hair, hair dyes are increasingly popular. Full colour, highlights or streaks, the options are numerous and allow everyone to bring some creativity to their hair. However, dyes are controversial due to their composition and the potentially harmful effects they could have on hair, health and the environment. Indeed, by opening the scales of the hair fibre cuticle, a necessary step to replace melanin, certain chemical agents found in permanent hair dyes are likely to weaken the fibres. That's why it's recommended for people with coloured hair to carefully choose the hair products they use.

Among the vegetable oils acclaimed for hair care, castor oil holds a prominent position. Indeed, in addition to hydrating and nourishing the fibres, this ingredient could potentially promote hair growth, a hypothesis that however requires further scientific research. Nevertheless, despite the numerous benefits of castor oil for hair, it is generally advised against using it on coloured hair. Indeed, according to some accounts, a loss of colour and a yellowing of the hair has been observed in individuals with coloured hair. It is presumed that this effect could be caused by the weakening of the strands during hair dyeing. The quality and quantity of castor oil, as well as the quality of the colouring itself, could also be implicated. However, it should be noted that this decolourising action of castor oil has only been observed during individual experiments by private individuals.

No scientific study to date has demonstrated that castor oil can strip hair dye. However, as a precaution, it is advisable to opt for another vegetable oil or a hair oil to care for coloured hair.

Castor Oil and Coloured Hair: A True Incompatibility?

If you still wish to benefit from the unique hair virtues of the castor oil, particularly its potential effect on hair growth, and you have coloured hair, be aware that there are a few tricks. Indeed, to minimise the risk of altering your colour, you can dilute the castor oil in a more suitable vegetable oil, such as argan oil or hibiscus oil. A 20% dilution, for example, could be beneficial. In addition to protecting your colour, this will reduce the high viscosity of the castor oil and make its application easier.