Oils, any oils, are occlusive by nature. Occlusives basically act as a barrier, wrapping round pores and skin or hair ideally retaining the great things in and the dangerous stuff out. That is why you high your water-based toners and lotions with an oil—you might be sealing within the hydration and vitamins beneath. It is a good factor.

It turns into an issue, nevertheless, when mentioned oil does not have any moisture to lock in—after which could also be actively retaining water out. This brings us again to utilization: Hair oils ought to be layered over water (be it on damp hair or from a water-based spray or cream), so that they have conditioning brokers to seal in; that is the primary situation. The second is that utilizing an excessive amount of hair oil could also be tougher to clean off within the bathe (particularly in the event you go for light, sulfate-free shampoos or co-washes). So then, since you’re not totally washing off the product, water out of your bathe is repelled, unable to soak in, leaving your hair dry, dehydrated, and brittle. 

(An addendum to this: For these with very high-porosity hair, the above situation may fit in your favor, as your strands have a tendency to soak up an excessive amount of water—inflicting swelling and breakage. However for these with common to low-porosity hair, oil buildup will result in brittleness.)

So why do I single out coconut oil right here? As a result of coconut oil is the one most probably wrongdoer. There are just a few causes for this. The primary, “Coconut oil tends to solidify some,” says board-certified dermatologist Raechele Cochran Gathers, M.D. (You understand how it is typically strong at room temperature? Yeah, kind of like that). Because it dries right into a strong, it might probably trigger strands to really feel stiffer and extra coarse—resulting in breakage.

However coconut oil is also excessive in lauric acid, which naturally attracts and binds with hair proteins. This may trigger protein buildup, resulting in much less elasticity and suppleness of hair—or frequent signs of brittleness.