Flu antiviral: what they do and when to use them

Got the flu and wondering if an antiviral will help? Flu antivirals are medicines that slow the virus so your body can recover faster. Used early, they can shorten symptoms and lower the chance of complications for people at higher risk. They’re not a replacement for the flu vaccine, but they can matter if you get sick.

Common flu antivirals

Here are the main options you’ll hear about:

Oseltamivir (Tamiflu) — oral pill taken for five days. Commonly prescribed, works best if started within 48 hours of symptoms, but doctors may give it later for severe cases.

Zanamivir (Relenza) — inhaled powder. It’s effective but can cause breathing problems in people with asthma or COPD, so tell your provider about lung issues.

Peramivir — IV antiviral used in hospitals for severe flu when oral or inhaled options aren’t suitable.

Baloxavir (Xofluza) — single-dose oral drug that works differently from others and can be an option for otherwise healthy people or those at risk. Timing matters here too.

Started early (ideally within 48 hours) these meds typically shorten illness by about one to two days and reduce complications in high-risk groups like older adults, pregnant people, young children, and people with chronic health problems.

Safety, side effects, and practical tips

Side effects are usually mild: nausea with oseltamivir, throat or breathing issues with inhaled drugs, or local reactions with IV meds. Serious reactions are rare but possible. Always check with your doctor or pharmacist if you have questions about interactions or allergies.

Resistance can happen, so doctors pick the best option based on local trends and your health. If you feel worse or don’t improve after treatment, contact your healthcare provider.

Want to buy antivirals online? Many countries require a prescription. If you choose an online pharmacy, look for clear licensing details, a real pharmacist contact, secure payment, and a requirement to upload a prescription. Avoid sites that sell prescription drugs without asking for one or that price drugs much lower than typical — that’s often a red flag.

Final practical tips: get vaccinated every year, start antivirals quickly if your doctor recommends them, and keep an eye on breathing and fever. If you’re unsure, call your healthcare provider — early advice often changes the outcome.

If you need help finding reliable online pharmacies or want to understand prescriptions and shipping rules, our site has guides to help you compare options safely.