HEllo Marwa ☺️👋
Sim Sensitive System 4 Scalp Tonic can leave a white residue for a few common reasons:
It contains active ingredients (like salicylic acid) that can crystallize as the product dries
This happens more often on fine hair, lighter hair, or sensitive scalps
Even when applied correctly to a clean scalp, some scalps just don’t absorb it fully
So this isn’t necessarily “product buildup” or user error — it’s often a formula–scalp compatibility issue, exactly like you suspected.
What you can try first (low-effort tests)
Before giving up completely, try one of these and see if it helps:
Apply less product than recommended
Apply it to a slightly damp scalp, not fully dry
Massage it in very thoroughly and lightly blow-dry afterward
If the white residue still appears → that’s a sign it’s not a good match for you 🩷
Have a nice day 🩷