For a lot of people, whey protein was the gateway supp—the first one they shelled out dough for in an effort to build a bigger, stronger physique. But that love affair never fades, and there’s a reason for that: it remains one of the safest, most effective supplements on the market.

Here, we give you the lowdown on what whey really is and why it continues to be a mainstay in supplement stacks everywhere.

Bodybuilder With Protein Shake

The Best (and Worst) Whey Protein Powders

Does your whey protein powder suck? Get a crash course on which powders pack a real punch.

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