Sales of the drug for cosmetic uses rose two-fold to $584 million in the second quarter, trouncing analysts' estimates of $483 million as vaccinations encouraged people to resume non-essential procedures after being holed up at home for months.

The company acquired the drug last year as part of its $63 billion purchase of Allergan. Company executives said on an earnings call that sales of products gained through the deal were on track to outpace Allergan's historical performance.

Increased investment in Botox and other aesthetic products is helping boost demand, Chief Executive Officer Richard Gonzalez said.

"About two-thirds of the performance, I think, is fundamental demand and maybe one-third of it is pent-up demand," Gonzalez added.

The company forecast full-year adjusted earnings between $12.52 and $12.62 per share, compared with $12.37 to $12.57 per share previously. Analysts expected 2021 earnings per share of $12.61, according to Refinitiv IBES data.

AbbVie also reported a 4.8% rise in quarterly sales of its best-selling drug Humira to $5.07 billion, roughly in line with expectations.

But sales of the drug, which is facing rivals in Europe, fell 6% on a reported basis in international markets while rising 7.1% in the United States.

AbbVie said the recent approval of Biogen's Alzheimer's disease drug had increased interest in treatments that clear brain plaques, a likely contributor to the disease.

The company expects to start testing a drug for Alzheimer's that works on the same mechanism by the end of the year or early next year.

Its shares were 1.7% lower at $116.88 in early trading.

(Reporting by Manas Mishra and Amruta Khandekar in Bengaluru; Editing by Aditya Soni)

By Manas Mishra and Amruta Khandekar