* Health index set for worst day since Nov. 22
* Pfizer top drag on S&P, J&J on Dow
* Dow up 0.28 pct, S&P up 0.04 pct, Nasdaq down 0.07 pct (Adds details, comments, updates prices)
By Yashaswini Swamynathan
Jan 11 (Reuters) - U.S. stocks slipped to session lows, before recovering ground, on Wednesday as drug stocks took a beating after Donald Trump's comments on drug pricing in his first formal news conference after his election victory.
The President-elect lashed out at pharmaceutical companies, saying they were "getting away with murder" by charging high drug prices.
Drug pricing has become a lightning rod for criticism with several drugmakers coming under federal investigation for price gouging.
The S&P 500 healthcare index, which reversed course following Trump's comments, was down about 1 percent and on track for its worst day since Nov. 22.
The Nasdaq biotechnology index lost 2.4 percent. Both indexes are on track to snap a six-day winning streak.
"We expect the U.S. biotech and pharmaceutical sector to be very volatile in the coming days and any mergers and acquisition will not be that easy," said Naeem Aslam, chief market analyst at ThinkMarkets UK.
The top five losers on the S&P 500 were healthcare-related stocks, led by Pfizer. Amgen weighed the most on the Nasdaq, while J&J was the biggest drag on the Dow.
"In times like this the expectation is for an erratic, choppy environment, however we have not got anything earth shattering," said Andre Bakhos, managing director at Janlyn Capital in Bernardsville, New Jersey.
At 11:59 a.m. ET (1659 GMT), the Dow Jones Industrial Average was up 55.17 points, or 0.28 percent, at 19,910.7, the S&P 500 was up 0.91 points, or 0.04 percent, at 2,269.81 and the Nasdaq Composite was down 3.68 points, or 0.07 percent, at 5,548.14.
Five of the 11 major S&P sectors were lower.
Energy stocks rose tracking a more-than-2-percent gain in oil prices. That helped limit losses.
Merck's near 3 percent rise and Goldman Sachs's near 1 percent increase helped keep the Dow afloat.
Lockheed Martin dropped about 1 percent after Trump said the F-35 fighter jet project "is way behind schedule and billions over budget."
Advancing issues outnumbered decliners on the NYSE by 1,678 to 1,146. On the Nasdaq, 1,434 issues fell and 1,255 advanced.
The S&P 500 index showed 14 new 52-week highs and two new lows, while the Nasdaq recorded 71 new highs and 11 new lows. (Reporting by Yashaswini Swamynathan in Bengaluru, Additional reporting by Tanya Agrawal; Editing by Savio D'Souza)