What to Take for a Viral Infection: Medications & Remedies

Most viral infections have no cure, so what you take depends on whether a targeted antiviral exists for your specific virus and, if not, which symptoms bother you most. For a handful of viruses, prescription antivirals can shorten illness or prevent serious complications, but they usually need to be started within the first day or two of symptoms. For the vast majority of viral infections, treatment comes down to over-the-counter medications for fever, congestion, and cough, along with a few supplements and home remedies that have decent evidence behind them. The trick is knowing which products actually work, which are a waste of money, and which can do real harm.

Prescription Antivirals and When They Matter

Antiviral drugs work by interfering with specific steps in a virus’s life cycle. Some block the virus from attaching to your cells, others prevent it from copying its genetic material, and others stop newly made viral particles from breaking free to infect more cells.¹ Because each antiviral targets a particular virus’s machinery, there is no broad-spectrum “antiviral pill” the way there are broad-spectrum antibiotics. You need the right drug for the right infection.

For influenza, the main options are neuraminidase inhibitors like oseltamivir (Tamiflu) and baloxavir (Xofluza). These drugs shorten flu symptoms by roughly a day on average, but only if you start them within about 48 hours of your first symptoms. After that window closes, the benefit drops off sharply.² That narrow window is one of the most frustrating things about antiviral therapy in general: by the time many people feel sick enough to see a doctor, the drugs are less effective.

For COVID-19, nirmatrelvir/ritonavir (Paxlovid) reduces the risk of hospitalization in people at higher risk for severe disease. It works by blocking a protease the virus needs to replicate. The ritonavir component isn’t there to fight the virus directly; it slows the breakdown of nirmatrelvir in your body so the drug stays active longer. That same mechanism, though, creates a significant problem: ritonavir powerfully inhibits a liver enzyme involved in metabolizing many common medications, which means Paxlovid can cause serious drug interactions.³ If you take blood thinners, certain heart medications, anti-seizure drugs, or immunosuppressants, your doctor needs to review every one of them before prescribing Paxlovid.⁴

For herpes viruses, including cold sores, genital herpes, and shingles, acyclovir and its prodrug valacyclovir are the workhorses. Valacyclovir delivers three to five times the amount of active drug into the bloodstream compared to plain acyclovir, which means you can take it less often.⁵ For shingles, starting treatment early speeds rash healing and reduces pain.

For RSV in infants, preventive monoclonal antibodies like nirsevimab have changed the game. Rather than treating infection after it starts, nirsevimab locks a key protein on the virus’s surface so it cannot enter cells, and a single dose provides protection for an entire RSV season.⁶ This approach has moved RSV prevention from something offered only to the highest-risk babies toward broader infant immunization.

Over-the-Counter Medications That Actually Help

When no prescription antiviral applies, your goal shifts from fighting the virus to managing symptoms while your immune system does the heavy lifting. The good news is that a few cheap, widely available medications work well. The bad news is that some popular products sitting on pharmacy shelves barely outperform sugar pills.

Fever and Pain

Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin) are the first-line choices for fever, body aches, headache, and sore throat during a viral illness. Both bring fevers down effectively. In head-to-head studies, ibuprofen tends to produce a larger temperature drop and keep the fever down longer than acetaminophen at similar doses.⁷ That said, acetaminophen is gentler on the stomach and is the better pick if you have kidney issues or are on blood thinners. You can also alternate the two, which some people find more effective than either one alone, since they work through different pathways.

Nasal Congestion

This is where things get interesting and slightly controversial. The oral decongestant found in most cold medicines sold in the United States today is phenylephrine, which replaced pseudoephedrine on open shelves after laws restricted pseudoephedrine sales to behind the pharmacy counter. The problem? Phenylephrine taken by mouth performs no better than a placebo for nasal congestion. In a controlled trial, pseudoephedrine significantly reduced congestion compared to both placebo and phenylephrine, while phenylephrine’s results were statistically indistinguishable from taking nothing.⁸ A systematic review confirmed this finding across multiple studies.⁹ The FDA eventually agreed and revoked phenylephrine’s status as an effective oral decongestant in 2023. If you want a decongestant pill that works, ask the pharmacist for pseudoephedrine from behind the counter.

Nasal spray decongestants like oxymetazoline (Afrin) are a different story. They work fast and work well because the drug is delivered directly to the swollen tissue. The common warning is that you should never use them for more than three days, or you will get “rebound congestion” that is worse than the original stuffiness. That risk is real with prolonged heavy use, though one study of healthy subjects found no rebound congestion or loss of effectiveness after four weeks of three-times-daily oxymetazoline use.¹⁰ Still, since most colds last less than two weeks, keeping spray use under five to seven days is a reasonable precaution in practice.

Runny Nose and Sneezing

If your main complaint is a constantly dripping nose and sneezing fits, the older “first-generation” antihistamines like diphenhydramine (Benadryl) or chlorpheniramine are more helpful than the newer non-drowsy ones. That seems backwards if you think antihistamines are just for allergies, but the older drugs block more than histamine receptors; they also block muscarinic receptors and cross into the brain, both of which appear to help suppress the sneeze reflex during a cold.¹¹ The newer antihistamines like loratadine (Claritin) and cetirizine (Zyrtec) do not cross the blood-brain barrier and are not particularly useful for cold symptoms. The tradeoff is obvious: the drugs that work make you drowsy.

Cough

For a wet, mucus-producing cough, guaifenesin (Mucinex) loosens secretions and makes coughing more productive. For a dry, hacking cough that keeps you up at night, dextromethorphan (found in Robitussin DM and many combination products) suppresses the cough reflex. Studies show both can produce measurable improvements compared to placebo, though the effect sizes are modest and some trials have found no benefit, likely due to a strong placebo effect in cough research.¹² A spoonful of honey may work just as well for cough, as described below.

Supplements and Natural Remedies Worth Considering

Zinc

Zinc lozenges are one of the better-supported natural remedies for colds. A meta-analysis of seven trials found that zinc lozenges shortened the duration of common cold symptoms by about a third, with zinc acetate lozenges reducing colds by roughly 40% and zinc gluconate by about 28%, though the difference between the two salts was not statistically significant.¹³ The catch is that the evidence is not universally positive. An earlier set of trials using experimentally induced rhinovirus colds found no benefit from zinc gluconate lozenges at all, with no reduction in symptom severity, duration, or viral shedding.¹⁴ The discrepancy probably comes down to dose, formulation, and how the lozenges were designed. Zinc needs to dissolve slowly in the mouth and release ions in the throat to have any local antiviral effect. Flavored formulations that bind the zinc ions (like those containing citric acid) can neutralize the active ingredient. If you try zinc lozenges, start them within 24 hours of symptom onset and look for products without citric acid.

Honey

Honey is surprisingly effective for upper respiratory symptoms, particularly cough. A systematic review found that honey improved overall symptom scores, reduced cough frequency, and reduced cough severity compared to usual care.¹⁵ In children, honey appears to reduce cough frequency about as well as dextromethorphan, the active ingredient in most OTC cough suppressants, and may be better than diphenhydramine for the same purpose.¹⁶ One important safety note: never give honey to children under one year old due to the risk of infant botulism. For everyone else, a spoonful of honey before bed is a cheap, well-tolerated option that performs as well as or better than many pharmacy cough products.

Vitamin C

Vitamin C is the remedy people reach for most instinctively when they feel a cold coming on, and the evidence supports a small but real benefit. Regular supplementation at one to two grams per day has been shown to shorten cold duration by about 8% in adults and 14% in children, and to reduce symptom severity as well.¹⁷ The key word is “regular.” Taking vitamin C only once symptoms appear does not seem to help much. If you want the benefit, you need to be taking it before you get sick. That 8% reduction in adults translates to roughly half a day shaved off a week-long cold, which is real but not dramatic.

Vitamin D

Vitamin D supplementation has been shown to protect against upper respiratory infections overall, with the biggest benefit going to people who are actually deficient in the vitamin.¹⁷ During the pandemic, researchers noted that deficiencies in vitamin D were common among patients with acute respiratory infections, and that vitamin D plays a role in maintaining the physical barrier against viruses and helps regulate the inflammatory response.¹⁸ If your levels are already normal, additional supplementation probably won’t help much during an active infection. But if you are deficient, which is common in northern latitudes, among older adults, and in people with darker skin, getting your levels up is one of the easier things you can do to lower your odds of respiratory illness in the first place.

Elderberry

Elderberry extract has a loyal following. A systematic review found that it may reduce the duration and severity of colds and the duration of influenza, though the evidence was rated as uncertain.¹⁹ One interesting finding from that review was that an elderberry-containing product was associated with fewer influenza complications compared to oseltamivir, though that comparison needs to be taken cautiously given the small study sizes. Elderberry is generally safe, but it does not appear to prevent you from catching a cold in the first place.

Home Remedies and Physical Comfort Measures

Beyond pills and supplements, a few simple interventions are worth your time.

Saline nasal irrigation, whether from a squeeze bottle, neti pot, or saline spray, is one of the most straightforward things you can do for congestion. A Cochrane review found that in children, saline irrigation reduced nasal secretion and breathing obstruction scores compared to standard care.²⁰ The evidence in adults was less impressive, with most results showing no difference from usual care. Still, saline irrigation has essentially zero risk and costs almost nothing. The main thing to remember is to use distilled, sterile, or previously boiled water rather than tap water, since rare but serious infections have been linked to contaminated neti pot water.

Steam inhalation is a remedy that most people assume is harmless, but it deserves a warning. While breathing warm, humid air can feel soothing, there is no proven clinical benefit, and the burn risk is significant, especially for children. Hospital records show a meaningful number of scald injuries from people, particularly kids, tipping bowls of hot water.²¹ A warm shower or a cool-mist humidifier provides similar comfort without the burn hazard.

Staying hydrated matters more than people realize. Fever increases fluid loss, and a stuffed nose forces mouth breathing, which dries out mucous membranes. Water, broth, and warm liquids all help keep secretions thinner and easier to clear. There is no magic number of glasses to drink. Just pay attention to urine color: pale yellow means you are doing fine.

What Not to Take

Antibiotics

Antibiotics kill bacteria. They do nothing to viruses. This is well understood in medicine but still not well understood by many patients, who pressure their doctors for a Z-pack every time they get a cold. Taking antibiotics for a viral infection does not speed recovery. It does expose you to side effects like diarrhea, yeast infections, and allergic reactions, and it contributes to antibiotic resistance, which is a genuine public health crisis. The only time antibiotics enter the picture during a viral illness is if a secondary bacterial infection develops, such as bacterial sinusitis or pneumonia layered on top of a viral cold or flu.

Aspirin for Children and Teenagers

Aspirin is contraindicated in anyone 18 or younger who has a suspected viral illness because of the risk of Reye’s syndrome, a rare but frequently fatal condition involving brain swelling and liver failure.²² Reye’s syndrome is most strongly associated with influenza B and chickenpox, and death occurs in about 30 to 40% of cases.²³ Even in adults, Reye’s syndrome has been documented, particularly in the setting of influenza.²⁴ Use acetaminophen or ibuprofen instead.

Corticosteroids Without Medical Supervision

Some people have leftover steroid prescriptions from past conditions and wonder whether a short course might help them feel better during a bad viral illness. For most viral infections, steroids can do more harm than good. In a meta-analysis of COVID-19 patients, glucocorticoid treatment was associated with delayed viral clearance, meaning the virus stayed detectable in the body for longer. The delay was dose-dependent: higher and medium doses carried a significant risk of delayed clearance, while low doses did not reach the same level of risk.²⁵ In transplant recipients with influenza, high-dose steroids similarly trended toward prolonged viral shedding.²⁶ Corticosteroids have a specific, life-saving role in severe COVID-19 pneumonia and certain other critical situations, but that decision belongs to a hospital team, not to self-medication.

Combination Products and How to Read a Cold Medicine Label

Walk into any pharmacy during cold and flu season and you’ll face a wall of brightly colored boxes promising total symptom relief. Most of these are combination products that bundle two, three, or even four active ingredients: a pain reliever, a decongestant, an antihistamine, and a cough suppressant. The marketing names (DayQuil, NyQuil, Theraflu, and dozens more) obscure what is actually inside.

The main risk with combination products is double-dosing on a single ingredient. If you take a “cold and flu” combo that contains acetaminophen and then also pop a couple of Tylenol for your headache, you may be taking twice the intended dose of acetaminophen, which is hard on the liver. Read the “Drug Facts” panel on everything you take and tally up any shared ingredients. Another issue is that combination products force you to take drugs you may not need. If your only symptom is congestion, you do not need a cough suppressant and an antihistamine mixed in. Buying individual ingredients lets you target what is actually bothering you and makes it easier to avoid unnecessary side effects like excessive drowsiness.

When choosing products, look past the brand name and check these specifics: whether the decongestant is pseudoephedrine or the ineffective phenylephrine, whether the antihistamine is a first-generation one that will actually dry secretions but also make you sleepy, and whether the product contains acetaminophen so you know not to take additional Tylenol. That five seconds of label reading is worth more than anything the marketing on the front of the box tells you.

When a Viral Infection Needs More Than Home Treatment

Most viral infections, including the common cold, run their course in a week or two without medical intervention. But certain red flags warrant a visit to a doctor or an emergency room. Difficulty breathing or shortness of breath, chest pain, a fever that persists beyond four or five days or spikes very high, confusion or difficulty staying awake, and inability to keep fluids down for more than a day are all signs that something more serious may be happening, whether that is a secondary bacterial infection, viral pneumonia, or dehydration that needs IV fluids.

People over 65, young children, pregnant individuals, and those with chronic conditions like diabetes, heart disease, or a compromised immune system face higher risks of complications from viruses like influenza, COVID-19, and RSV. For these groups, early contact with a healthcare provider is especially important because it opens the door to prescription antivirals within the window when they are most effective. Waiting a few days “to see if it gets better” can mean missing the 48-hour treatment window entirely, turning a treatable situation into one where the best remaining option is supportive care and hope.