As millions of Americans brace themselves for a massive blizzard, a handful of health-care stocks have been heating up the charts over the past few days. Here they are -- three of the most humongous performers for this week.

Overcoming peer pressure
Strong earnings and great guidance will do the trick nearly every time. Both certainly helped shares of USANA Health Sciences (USNA -1.16%) this week. The network marketer of nutritional supplements and weight-management products saw shares jump 24% over the past few days.

USANA reported earnings for last quarter of $1.27 per share, handily beating analyst estimates of $1.21 per share. The company beat on revenue also, posting sales of $168.5 million compared with the $165.6 million total that analysts expected. With 2013 guidance also well above analysts' views, a huge stock surge isn't surprising.

However, USANA's success this week came in spite of peer pressure of sorts. The ongoing controversy stemming from attacks by hedge fund manager Bill Ackman on Herbalife (HLF 2.47%) have hurt several multilevel marketing companies. With this week's nice gains, USANA has climbed back above where the stock was before Ackman's public allegations that Herbalife is a pyramid scheme. 

Surprise, surprise
Neurocrine Biosciences (NBIX -2.17%) is another company in the health-care sector with good earnings news. Shares jumped 21% this week following Neurocrine's announcement of fourth-quarter results.

Analysts were expecting the small biotech to report a loss of $0.08 per share. Neurocrine surprised them with positive earnings of $0.14 per share. Revenue of $21.9 million was nearly twice the level from fourth quarter of 2011.

The surprise bonus stemmed from the company's collaboration with AbbVie (NYSE: ABBV) on elagolix. The drug, which targets treatment of pain associated with endometriosis, is in late-stage clinical studies. Elagolix is also part of a phase 2 study in helping treat uterine fibroids.

Revenge of Provenge?
After shares fell off a cliff back in August 2011 because of disappointing sales of prostate cancer drug Provenge, Dendreon (NASDAQ: DNDN) has been on a tear lately. Shares increased more than 16% this week.

Dendreon's big move this week is likely to stem from several factors. Probably the most important is anticipation that Provenge could gain a positive recommendation from a key European committee as early as the first quarter of this year. Another related catalyst is that analysts are more bullish on the stock these days. Sanford C. Bernstein analyst Geoffrey Porges thinks urologists will use Provenge at a much higher rate in 2013. Cantor Fitzgerald recently raised its price target for Dendreon to $7 per share, a level the stock now hovers near.

Dendreon fueled this positive buzz last month, when it provided earnings guidance higher than what analysts were expecting. While it's been a long road and there are probably plenty of potholes and detours ahead, shareholders just might yet see Provenge get some measure of revenge with naysayers.

Lagniappe
The Super Bowl is over, but in honor of the New Orleans tradition of lagniappe, this week's humongous list of health-care news offered a little something extra from humongous health-care stock Oncolytics Biotech (ONCY -7.02%).

Oncolytics shares jumped 12% this week, and nearly 22% on Friday, after the company announced positive results from a phase 2 study of cancer drug Reolysin. Of the patients with squamous cell carcinoma of the lung, 95% experienced shrinkage of their tumors. The average tumor-size reduction for all patients in the study was 33.7%.  

It should be noted that there were only 20 patients in this study, and good results from early and mid-stage studies with small sample sizes don't always translate to similar results from larger studies. But good news is still good news. As they say in New Orleans, Laissez les bons temps rouler. Let the good times roll.