Herbalife came out swinging Thursday against claims made by hedge fund manager William Ackman that the business amounts to a pyramid scheme.

A series of executives looked to refute Ackman’s allegations during an analyst and investor meeting, laying out everything from how the business operates to who its customers are.

Critics have questioned the company’s business model, which uses a network of distributors to sell its nutritional supplements and weight-loss products in more than 80 countries.

The defense put forth by Herbalife Thursday comes a few weeks after Pershing Square Capital’s Ackman alleged Herbalife Ltd. was a pyramid scheme and that he was shorting the stock. Short-sellers make money when the shares they’re betting against decline.