Allergan topped analysts' estimates for quarterly profit and raised its forecast for annual earnings, led by stronger demand for medical aesthetic products including Botox.
Wall Street analysts had widely expected Allergan to lift its profit forecast thanks to higher Botox revenue as well as the lack of generic copies in the market of its second most important drug, Restasis.
Sales of Botox, the blockbuster wrinkle treatment, climbed 14.5% to $934.5m in the second quarter of 2018, exceeding analysts' estimates.
Allergan faces looming competition for key products including eye disease drug Restasis and vaginal cream Estrace, as exclusive patents on the drugs expire.
While there are already generic versions of Estrace, Allergan has tried to delay the launch of generic copies of Restasis.
Last year, it transferred patents on Restasis to a Native American tribe to shield them from review by an administrative court.
However, a US appeals court last week said that a tribunal run by the US Patent and Trademark Office has authority to review the validity of patents covering Restasis.
Second-quarter sales of the drug fell 5.5%, partly due to lower prices.
Allergan's medical aesthetics revenue grew 15.5% to $743.6m, helped by Botox as well as the CoolSculpting system that helps people slim down by freezing fat away.
Excluding one-time items, the drugmaker earned $4.42 per share, topping analysts' average estimate of $4.13.
The company reported a smaller net loss attributable to ordinary shareholders of $472.5m, or $1.39 per share, in the second quarter ended June 30, from $795.5m, or $2.37 per share, a year ago.
The company said its revenue rose 2.9% to $4.12 billion.
It raised its full-year forecast for adjusted profit to between $16 and $16.50 per share, from an earlier estimate of $15.65 to $16.25.
Allergan also said it had authorised a new $2 billion share buyback programme.