Answer first
Cosmetics sold in Malaysia carry a notification number (starting with NOT) that you can look up on the official NPRA cosmetic notification portal to confirm the product has been notified. It helps you check a product is listed, but it is a notification, not an approval of any claim about results.
How to check
Find the NOT number on the box, search it on the NPRA portal, and check the product name and company match.
What it tells you
That the product has been notified as a cosmetic in Malaysia.
What it doesn't tell you
Whether a product works, or whether claims in adverts are true.
Questions
No number on the box?
Be cautious and ask the seller; genuine notified cosmetics show it.
Is a notified product always safe for me?
Patch-test and stop if you react; allergies are personal.