STORY: Eli Lilly said Monday it will ship the two highest doses of its popular weight-loss drug Zepbound to cash-paying customers on its website starting early August.

That will make doses up to 15 milligrams available in single-dose vials online for $499 per month or less, regardless of insurance status.

Lilly and rival Novo Nordisk started offering vials at discounted prices on their respective websites to expand access and stave off competition from compounded versions or cheaper copies of their weight-loss drugs.

The LillyDirect website was launched last year to help patients directly order some drugs.

In February, it reduced the price of Zepbound vials and expanded the range of doses for patients who choose to pay cash through the website.

In May, CVS Health said it had decided to drop Zepbound from some lists of medicines it covers for reimbursement from July 1 but would keep reimbursing for Novo Nordisk's Wegovy after negotiating a more favorable price from the Danish drugmaker.

Both Lilly and Novo have been competing in the potential $150 billion obesity drug market.

But recent prescription data shared by analysts indicates Lilly has taken the lead, overtaking Novo despite its initial first-mover advantage.