Your Sunscreen Has an Expiry Date. Your Moisturizer Does Not.

When I started sourcing for the health and beauty boxes, the first thing I did was go looking for expiration dates. I found them on some things and not on others, and at first it looked completely arbitrary.

It is not arbitrary at all. It comes down to a single question, and the answer is printed right on the back of the bottle.

That distinction is doing all the work here, and it is a legal one rather than a marketing one.

Flip the product over and look for a boxed label headed Drug Facts, with Active Ingredients, Uses and Warnings inside it. If it is there, the product is legally a drug. Drugs have to be stability tested, and the FDA requires them to carry an expiration date.

More of your bathroom lands in that category than you would guess:

• Sunscreen, and any moisturizer or makeup carrying an SPF claim
• Acne cleansers and treatments
• Anti-dandruff shampoo
• Antiperspirant, though not plain deodorant
• Fluoride toothpaste

All of those are drugs, or cosmetics and drugs at the same time, and every one of them has to tell you when it expires.

This is the part that genuinely surprised me. In the FDA's own words: "There are no U.S. laws or regulations that require cosmetics to have specific shelf lives or have expiration dates on their labels."

None. A moisturizer, a lipstick, a body wash, a plain shampoo. Legally, they can tell you nothing at all about how old they are or how long they will last.

Most beauty products carry a small icon of an open jar with a number and the letter M beside it. That is the Period After Opening symbol, and it is the number that actually matters.

• 6M means six months after opening
• 12M means twelve months after opening
• 24M means twenty four months after opening

The number is set by the manufacturer based on their own testing, not by a fixed rule, so it varies product to product. Europe requires the symbol on anything lasting longer than thirty months, unless the idea of opening the product does not really apply to it, which is why you see it on most name brands sold internationally.

Here is the bit most people miss. That twelve month clock does not start until somebody opens the thing.

A sealed jar that has been sitting in a warehouse for a year has not used up a single month of its twelve. Which is why how old is it is the wrong question, and has it been opened is the right one.

I want to be straight about the limits of that, though. Sealed is not the same as forever. Products still age in the container and storage conditions matter. But sealed does mean the clock has not started, and it is the single biggest reason I will not put anything opened or half used into a box.

If you resell, this is also the answer to the question you will get asked most. No, it has not been sitting open, and here is the symbol that proves the clock has not started.

Look for a short string of letters and numbers stamped into the bottom of a bottle or crimped into the end of a tube. That is the batch code, and for a lot of brands it encodes when the product was manufactured.

There are free batch code decoders online. You pick the brand, type in the code, and get a manufacture date back. They work well on major brands and they are hit and miss on store brands.

Full disclosure on that last part, because it applies directly to what I sell. A good amount of what goes into my boxes is unbranded, and unbranded stock is exactly where those decoders come up empty. So I do not lean on a lookup tool. I check dates and packaging condition by hand, one item at a time. It is slower, and it is the only thing I actually trust.