I found this article; it says it can cause buildup on the hair. I have never used it on my hair, only my scalp.
I know you've heard a lot about products that should be avoided when you have Dreadlocks and much of the information is confusing. In this section, we'll do our best to explain the No-No's in a way that cuts through the confusion. Let's get started...
SHEA BUTTER: I love shea. It's great for use on dry skin which some people believe makes it great for use on dry scalp. The problem with shea is that like all butters, it has a degree of waxiness to it. Sometimes we confuse waxiness with oilness and it's not the same thing. Shea is actually dull and has little luster.
This waxy property rates it as a C+ in terms of holding dreadlocks but overall it results in a Grade of F over the long term as shea is difficult to shampoo out and builds up on hair. Not to mention, it doesn't shine so twisting into your dreadlocks may hold them but don't expect them to look shiny and healthy.
Most people who use shea butter, particularily, the raw (yellow variety), develop splotchy, white patches that resemble clumps of lint throughout their dreadlocks. Because dreadlocks are tightly matted, removing shea is cumbersome and thus you should AVOID using shea butter stand alone.
Thw abovephoto of naaniMODEL SOULSISTA is a pretty good example of how shea butter can accumulate in dreadlocks. Although difficult to see, the white specs you see in her hair are mainly the result of raw shea butter Build-up.
With that said, this does NOT mean that you should avoid products that contain shea butter. It is indeed excellent at alleviating dry skin. What this does mean is that if it is used in too high a concentration, you increase your chances of getting negative results. A product that contains shea should be formulated for use on the scalp primarily as well as the hair. Meaning, it should be light and creamy. Think about it, If the main objective of shea butter is to help dry skin (scalp), then you want it on your scalp to do its work. Because it's waxy NOT oily, it doesn't add sheen to the hair on its own. Sheen in products containing shea butter is often the result of other oils and butters.