Ahhh ok. I will look for them. This may be a stupid question, but are they only on the darkweb?
No. They're actually only on clear net. That's why I mentioned it as you might find it easier to navigate but you do need to be careful to some extent. Maybe use a prepaid card or something other than your bank to make payment. As they sell illegal stuff it's best to assume they can't be trusted with that stuff. Also make sure to look for pills that come in blister strips and original packaging rather loose pills.
They can often be found in post work out or sleep aid sections of their web stores.
Oh and make certain to use domestic sites. Any sites that ship from outside your country will have to cross a boarder and run the risk of losing your goods.