Is vitamin C serum actually worth it?

It's a bit of marketing hype. You'll only see results if your skin is really dull or if you use it regularly for months! That said, if you don't have much budget to spend on it, a good simple moisturizing cream already does 80% of the work.

The thing that really makes a difference is not slapping just any vitamin C serum on just any skin - it needs to be stable and in a decent concentration, otherwise yeah it's just marketing. A vitamin C that's turned orange or brown is oxidized and does nothing. Check the opening date and store it in the fridge or somewhere dark, that's not optional.

What people don't often mention is that you really have to use it regularly to see anything. Not just once a week when you remember. If you use it every day, like 2-3 months minimum, that's when you'll notice a real difference in brightness and fine lines. But it's work, you have to be consistent.

After that, honestly if you don't have a ton of cash to throw around, you can also start with lighter doses or cheaper alternatives that do a decent job. What matters is consistency, not the price of some fancy bottle. And if your skin doesn't tolerate pure vitamin C, there are gentler derivatives you can try.