It might be just build-up. If a clarifying shampoo (followed by deep treatment) doesn't help, then you might look into your products, if they have proteins in them. Some hair gets like that when it has had too much proteins. If that's the case, remove all the protein-y products from your usage for now and only use moisturizing products. Your hair should be back to normal after few week, more or less depending on many things.
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