Ever since I started my fitness regimen five months ago, GNC has become a store I've been giving a lot of business to. My only real complaint with GNC is that some of their products can be really expensive, though that's where the real negativity ends.
GNC offers a myriad of products for a myriad of health uses. There's quality products available to lose weight, gain muscle, improve sexual health, digestive cleansing, and so fourth. They also have a great return policy where if you're not satisfied with something you bought, you can return it for a full refund or exchange it with a product of equal or lesser value as long as you return it within 30 days of purchase and bring your receipt.
GNC customers can also sign up for a Gold Card, which gives you discounts on products sold in GNC's stores (brick and mortar or online), and if you keep your eyes pealed for "one day only" sales online, you can sometimes take advantage of said online sale AND use your Gold Card to cut off a good chunk of the price on something you plan to buy. I recently managed to snag a container of GNC Pro-Performance AMP Amplified Mass XXX for only $50 (including tax and shipping), whereas if I bought it online at the shelf price (including tax and shipping), it would have cost me around $83 (its price without tax or shipping is $76).
If you're looking to buy products that are aimed at helping you improve certain aspects to your health, GNC is certainly a place to check out.