Here’s what consumers have asked with answers from Timeless Skin Care staff and previous consumers.
There are some other popular vitamin C serums, some of which also include Vitamin E and Ferulic Acid. Skinceuticals, Drunk Elephant, Derma Doctor, Paulas Choice, to name a few but the price is generally higher, although the product is not necessarily a lot better. Have a look here for comparisons https://www.health.com/beauty/vitamin-c-serum
I find it easier to buy stuff off Amazon as I'm comfortable with that. But I hear that in some cases there is no reply if the product is oxidised or there's some issue. Timeless on the other hand has an excellent online store, with a very reachable helpline.
I started using this a year ago, and I really like the way it works. Getting a whole load of compliments about how fresh my skin looks.