A product memory, not another perfect routine.
Keep track of what you used and what you noticed. Even when the answer is “I am not sure.”
My Shelf is part of the iPhone release candidate now in final testing. It brings owned products, a wishlist and previously used products into one personal history.
Start with the product you already have
Save a scan, choose a catalog product or add a name manually. A missing label does not stop you from recording an experience. Edit the name and category or add the label later.
Keep timing with the experience
Record a start or stop date, frequency, pauses and why you stopped. Add dated observations for the body areas you used it on. Hair can feel good while your scalp feels dry; a single good/bad score would lose that distinction.
Compare without declaring a culprit
Compare two saved products, their shared and different ingredients, selected matches and dated experiences. A shared ingredient is something to investigate, not proof of what caused a reaction. The app does not automatically blacklist it.
Keep the label you actually tried
When you add a replacement label, earlier experiences retain the ingredient snapshot available at the time. A newer package or a revised database check does not rewrite what you recorded.
Your history stays useful
Personal Shelf and experience records are stored on your device for this launch. Export and import a backup from Settings. Browser checker preferences do not sync to your iPhone; there is no cloud account to keep them together.
What My Shelf does not do
It does not diagnose an allergy, identify the ingredient responsible for a symptom, or tell you to deliberately retry something that caused a reaction.