Here's a guide to help you make sense of the huge array of treatments available when a cold sidelines you or your family.

&byline;PROVEN EFFECTIVE

Topical decongestants: Afrin, Neo-Synephrine, Vicks Sinex — all oxymetazoline

Verdict: "Nose shrinkers" are what doctors call these sprays because they work so well in reducing swollen nasal passages. "Don't use them for more than three to four days because you become dependent on them," says J. Owen Hendley, professor of pediatrics at the University of Virginia. If you do become dependent, expect to get a stuffy nose equal to or worse than the original cold symptoms when you quit.

Analgesics: Advil (ibuprofen), Aspirin (acetylsalicylic acid), Tylenol (acetaminophen)

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Verdict: They can "make you feel a little better even if you don't have a fever," Hendley says, by relieving headaches and the general discomfort that comes with a cold.

Antihistamines: Benadryl (diphenhydramine), Clistin (carbinoxamine), Tavist (clemastine), Chlor-Trimeton (chlorpheniramine), Dimetane (brompheniramine).

Verdict: These drugs dry out secretions, but they make you very sleepy, experts say. So if you use them, take them before going to bed. And stick with these older, original antihistamines. Newer antihistamines — Claritin and Zyrtec, for example — have no proven effectiveness against cold-related symptoms, according to the American College of Chest Physicians (ACCP).

Antihistamines: Andehist; Bromfed; Dimetapp Cold and Allergy Elixir; Lodrane — all brompheniramine and timed-release pseudoephedrine

Verdict: The ACCP says there's strong evidence that this combination has benefit in treating coughs associated with the common cold.

Oral decongestants: Dimetapp; Drixoral; PediaRelief; Sudafed; Triaminic — all pseudophedrine.

Verdict: These products may help you breathe better. Effects are very modest. If you have high blood pressure or heart problems, check with your doctor before using these medications.

INCONCLUSIVE

Mucus thinners and expectorants: Mucinex (guaifenesin)

Verdict: Used for a couple of decades, this foul-tasting liquid is a common ingredient in nonprescription cough syrups. More recently, it has been formulated into a pill, making it easier to swallow. There's little evidence that it can thin mucus, says Hendley, but "it's worthwhile trying."

Saline nasal washes: Breathe Right Moisturizing Saline Spray; Simply Saline — all purified water and sodium chloride

Verdict: There are no definitive studies of these products' effectiveness, but rinsing the nose with saline helps wash away mucus, which could help relieve blocked nasal passages. "It's completely safe," says U-Va.'s Turner. "So if it makes you feel better, fine."

INEFFECTIVE

Combination drugs: Dayquil; Nyquil; Theraflu — all various ingredients including: acetaminophen, chlorpheniramine, dextromethorphan, doxylamine, diphenhydramine, guaifenesin

Verdict: The ACCP says to skip the combination medicines — advice echoed by other experts to prevent overdosing and getting ingredients you may not need. "They promise to do everything," notes Turner, "but you can get into some trouble." Better, he says, to find single-ingredient products.

Cough suppressants: Robitussin DM; Delsym; Vicks 44E; Buckley's — all dextromethorphan

Verdict: There's so little evidence for effectiveness in treating cold-related coughs that the ACCP strongly discourages the use of these popular medications, especially for children 14 years and younger.

Echinacea

Verdict: This popular herb is widely used for both treatment and prevention of colds. But the studies examining its effects have often been flawed. In 2005, the National Center for Complementary and Alternative Medicine found that it did little to prevent or shorten colds. "We really don't see any clinically signficiant effects," says Turner. Experts say save your money.

Vitamin C (ascorbic acid)

Verdict: A 2004 Cochrane Review of 29 studies involving more than 11,000 people found no evidence to justify giving megadoses of vitamin C to prevent colds in the general population. Taking up to four grams of vitamin C at the start of a cold also did not show any benefits.

Antiviral tissues: Kleenex (virucidals)

Verdict: Purportedly kills the two leading cold viruses, two types of influenza viruses and respiratory syncitial virus within 15 minutes of their being in the tissue. But there's no evidence that killing viruses in tissues helps to reduce, treat or prevent colds. "It only takes one virus particle to infect you," Hendley notes.

Zinc lozenges: Cold-Eze (zinc)

Verdict: "There have been an awful lot of studies done on zinc," but results have been inconsistent and so modest that they are not clinically significant, Turner says.

Homeopathic zinc solutions: Zicam Cold Remedy (minuscule amounts of zinc)

Verdict: In 2006, the maker of Zicam agreed to pay $12 million to settle 340 lawsuits brought by consumers who claimed the product's nasal gel damaged or destroyed their sense of smell. The company said the agreement was not an admission of liability but an effort to end most of the litigation over the homeopathic remedy. "Can I imagine putting that stuff in my nose?" says Hendley. "It's hooey."