Over years or decades, chronic hepatitis C can lead to serious complications, including fibrosis (buildup of scar tissue), cirrhosis (severe scarring) and hepatocellular carcinoma, the most common type of liver cancer. In the most severe cases, the liver can no longer carry out its vital functions and a liver transplant may be necessary.

Fortunately, today’s direct-acting antiviral (DAA) therapies are highly effective and easy to use. They’re taken as pills for just two or three months and have few side effects, and almost everyone can be cured. This is a big change from the older interferon-based treatment, which required weekly injections for six months or a year, caused difficult side effects and cured only about half of treated patients.

Which DAA regimen to use depends on several factors, including liver disease severity, other health conditions, previous treatment attempts and hepatitis C virus (HCV) genotype. Some medications work only against specific genotypes, but the newest ones work against all of them.

Hepatitis C treatment guidelines are simplest for adults who are being treated for the first time, do not also have hepatitis B, are not pregnant and do not have cirrhosis. Most people with such straightforward cases won’t need to see a specialist and can be treated by their primary care doctor.

The recommended regimens for this group are Epclusa (sofosbuvir/velpatasvir) or Mavyret (glecaprevir/pibrentasvir). These medications work against all HCV genotypes, so genotype testing is usually not needed before treatment. Most people with compensated cirrhosis, meaning they haven’t yet developed decompensated cirrhosis, or liver failure, can also use these regimens.

People using Epclusa take one pill once daily with or without food for 12 weeks. People using Mavyret take three pills at the same time once daily with food for eight weeks. DAAs are safe and well tolerated, and many people experience no side effects.

Other treatment options require genotypic testing. Previously untreated people with HCV genotypes 1, 4, 5 or 6 who have no cirrhosis or compensated cirrhosis can use Harvoni (sofosbuvir/ledipasvir) for 12 weeks. Those with genotypes 1 or 4 may also use Zepatier (grazoprevir/elbasvir) for 12 weeks.

Treatment decisions are more complicated for people who were previously treated for hepatitis C. These individuals as well as people with decompensated cirrhosis, liver cancer or severe kidney disease, liver transplant recipients, pregnant people and children with hepatitis C should work with a specialist to determine the best treatment strategy.

When hepatitis C treatment is working, the virus usually becomes undetectable within several weeks. People are considered cured when they still have undetectable HCV 12 to 24 weeks after completing treatment. Nearly everyone can be cured with the new meds, and if treatment doesn’t work the first time, trying again with a different regimen is usually successful.

Once a person is cured, they are very unlikely to relapse. But having hepatitis C does not lead to immunity, and it’s possible to get the virus again. Successful treatment halts liver disease progression, but some existing liver damage may be permanent. People who have already developed cirrhosis should undergo regular monitoring to catch liver cancer at an early, more treatable stage.