Viagra: How It Works, Dosage, Side Effects and Safe Buying Guide

Viagra is a pill most people know for treating erectile dysfunction (ED). It contains sildenafil, which relaxes blood vessels in the penis so more blood can flow in during sexual arousal. If you’ve never tried it, or you’re thinking about buying it, here’s what you need to know in plain language.

How Viagra Works and Who Can Use It

When you take Viagra, the drug blocks an enzyme called PDE5. Blocking this enzyme lets a chemical called cGMP stay longer, and cGMP is what makes the smooth muscles relax. The result is a firmer, longer-lasting erection when you’re sexually stimulated. The pill doesn’t work on its own – you still need arousal to get an erection.

Most men with mild to moderate ED can take Viagra safely, but there are a few groups who should avoid it. If you’re using nitrates for chest pain, have severe heart disease, or have low blood pressure, the combination can cause a dangerous drop in blood pressure. Also, men with a history of certain eye problems or severe liver/kidney disease need a doctor’s go‑ahead.

Typical dosing starts at 50 mg, taken about an hour before sex. If that’s not enough, a doctor may recommend 100 mg; if you feel side effects, you can drop to 25 mg. The pill works for up to five hours, but that doesn’t mean you’ll stay erect the whole time – it just gives you a window when the drug is active.

Buying Viagra Online: What to Check

Lots of sites promise cheap Viagra with no prescription. While a few legitimate online pharmacies do require a prescription, many shady sites sell fake pills that contain no sildenafil or dangerous fillers. Here’s a quick checklist to keep you safe:

  • Look for a pharmacy that asks for a valid prescription from a licensed doctor.
  • Check that the site displays a physical address, a phone number, and a pharmacist’s contact.
  • Make sure the site is certified by a recognized pharmacy verification program (e.g., NABP’s VIPPS in the US).
  • Read customer reviews, but be skeptical of overly glowing testimonials that sound scripted.
  • Avoid sites that price Viagra dramatically lower than normal market rates – if it looks too good to be true, it probably is.

When you receive the medication, inspect the packaging. Real Viagra comes in a blue, diamond‑shaped tablet with “PFIZER” and a batch number printed. If the pill looks off‑color, misshapen, or has no clear markings, discard it and contact a pharmacist.

Common side effects include headache, flushing, upset stomach, and mild vision changes. Most people find these tolerable, but if you experience a painful erection lasting more than four hours (priapism) or sudden vision loss, seek medical help right away.

In summary, Viagra can be a helpful tool for many men dealing with ED, provided you use it correctly and source it from a reputable pharmacy. Talk to your doctor about the right dose, check the safety checklist before you order, and watch for side effects. With the right approach, you’ll get the benefit you need without unnecessary risk.