Yes, that is usually fine. A silk pillowcase reduces friction, so hair worn down often tangles less and frizzes less than it would on rough cotton.

That said, loose hair can still knot up from tossing and turning, especially if your hair is long or curly. If you often wake up with tangles, a loose braid or a soft scrunchie can help without pulling too tight. A silk sleep cap is also an option if you want maximum protection.

Keep your pillowcase clean because hair products such as oils, leave in conditioner, or gel can build up and make the surface feel less fresh. A simple routine is to gently detangle before bed and wash the pillowcase regularly.