Lifestyle tips

Absolutely too good to be true. Snake oil. Save your money.

There are medications that do increase appetite, some of which are available without prescription.

* This post does not constitute medical advice. 🧐

I have seen medications to increase appetite but they all have required prescription from a doctor

I am not recommending that you research cyproheptadine. 👀

Eeeeeeeeh ...

Are they full of calories? Yes. Should you go hog wild with them? No.

Mass gainer is high in protien. And unless you wanna mess up your kidneys, you shouldn't go crazy with them.

Honestly, you can add calories in more enjoyable ways like putting cheese and sauces on stuff or switching to whole milk instead of slim milk.

Little changes add up in big ways.

As Munchies says, shakes tend to be high protein, as they're intended for supplementing when trying to add muscle mass. There are carbohydrate-based shakes available, but there are much more enjoyable ways to consume carbs.

Heavy cream shakes seem to be generally regarded as the most effective "supplementary" source of calories.

Medication does sound like it'll help skip the work to expand your appetite and help do it sooner, but (like some people have already said), that's not to say you by your self can't expand your appetite by eating a little more every day and trying to expand your capacity with specific foods.
It's good that you checked in here first, a lot of these people can give legitimate advice and alternatives.