Hepatitis B & C and Sex: Transmission Risk, Testing & Vaccination Questions (UK)

Hepatitis B & C and Sex: Transmission Risk, Testing & Vaccination Questions (UK)

Can you get hepatitis B from sex? It is a question that many people ask — and the answer is yes, hepatitis B can be transmitted through sexual contact. However, the picture is more nuanced than a simple yes or no. Hepatitis B and hepatitis C are both viral infections that affect the liver, yet they differ significantly in how they are spread, particularly through sexual activity. Many people associate hepatitis with blood-borne transmission — needles, transfusions, and medical procedures — but sexual transmission is a genuine and important route, especially for hepatitis B.

Understanding the difference between these two infections, how they are passed on, and what you can do about them is essential for making informed decisions about your sexual health. Testing provides reassurance and clarity, and vaccination plays a significant protective role for hepatitis B specifically.

Our clinic provides private STI testing services. We do not provide GP services or specialist liver care, but if further medical assessment is needed, you will be signposted to your GP or specialist service. In this guide, we explain what hepatitis B and C are, how they are transmitted sexually, when to consider testing, and the role of vaccination.

What Are Hepatitis B and Hepatitis C?

Hepatitis B and hepatitis C are both viral infections that target the liver, but they are caused by different viruses and behave differently in the body.

Hepatitis B is caused by the hepatitis B virus (HBV). It can be transmitted through contact with infected blood, semen, vaginal fluids, and other body fluids. Sexual contact is one of the most common routes of hepatitis B transmission worldwide.

Hepatitis C is caused by the hepatitis C virus (HCV). It is primarily a blood-borne virus, meaning it is most commonly spread through direct blood-to-blood contact — for example, sharing needles or through unscreened blood products. Sexual transmission of hepatitis C is less common but can occur in certain circumstances.

Both infections can present as either acute or chronic:

• Acute infection — a short-term illness that occurs within the first six months after exposure. Some people clear the virus naturally during this phase.
• Chronic infection — when the virus remains in the body long-term. Chronic infection can lead to ongoing liver inflammation and may require specialist monitoring.

It is worth briefly noting that hepatitis A also exists but is transmitted primarily through contaminated food and water. It is not typically considered a sexually transmitted infection in the same way as hepatitis B, although it can be passed through certain sexual practices. This guide focuses specifically on hepatitis B and C in the context of sexual health.

Can You Get Hepatitis B from Sex?

Yes — hepatitis B can be transmitted through sexual contact. The hepatitis B virus is present in blood, semen, and vaginal fluids, which means that unprotected vaginal, anal, or oral sex with an infected person can carry a risk of transmission.

Key points about hepatitis B sexual transmission include:

• Unprotected sex is the most significant risk factor — the virus can enter the body through mucous membranes during sexual activity
• Higher viral load in the infected person increases the likelihood of transmission
• Anal sex may carry a higher risk due to the potential for small tears in the lining of the rectum
• Oral sex carries a lower but not negligible risk, particularly if there are cuts or sores in the mouth
• Multiple sexual partners increases overall exposure risk over time

Hepatitis B is, in fact, more easily transmitted sexually than hepatitis C or even HIV. The virus is highly resilient and can survive outside the body for several days, making it more transmissible in certain situations.

However, it is important to maintain perspective. Not every sexual exposure to hepatitis B results in transmission. Risk varies depending on the type of sexual contact, whether the infected partner has a high viral load, and whether the uninfected partner has been vaccinated. Condoms significantly reduce the risk of hepatitis B transmission, although they do not eliminate it entirely.

Hepatitis C and Sexual Transmission

Hepatitis C sexual transmission is less common than hepatitis B transmission, but it does occur. HCV is primarily a blood-borne infection, and the most efficient route of transmission is through direct blood-to-blood contact.

However, sexual transmission of hepatitis C can happen in certain circumstances:

• Sexual practices that involve blood exposure — including rough sex, sex during menstruation, or practices that cause small tears or abrasions
• MSM (men who have sex with men) populations — research has identified higher rates of hepatitis C sexual transmission among MSM, particularly where there are co-infections such as HIV
• Presence of other STIs — existing genital infections or inflammation may increase vulnerability to HCV transmission

For the general heterosexual population in monogamous relationships, the risk of hepatitis C sexual transmission is considered low. However, the risk is not zero, and in certain contexts it is higher than many people assume.

The key difference between hepatitis B and C in terms of sexual transmission is magnitude. Hepatitis B is readily transmitted through sexual contact because the virus is present in high concentrations in sexual fluids. Hepatitis C, by contrast, is primarily found in blood, with much lower concentrations in semen and vaginal secretions.

Hepatitis Symptoms: What to Look For

One of the challenges with both hepatitis B and hepatitis C is that they are frequently asymptomatic, particularly in the early stages. Many people carry the virus without knowing it, which is why testing is often the only way to detect infection.

When hepatitis B symptoms do occur, they may include:

• Fatigue — persistent tiredness that does not resolve with rest
• Jaundice — yellowing of the skin and the whites of the eyes
• Dark urine — urine that appears darker than usual
• Pale stools — lighter-coloured bowel movements
• Abdominal discomfort — particularly in the upper right area, where the liver is located
• Nausea or loss of appetite
• Joint pain or general malaise

Hepatitis C symptoms, when they appear, are often similar — fatigue, jaundice, and abdominal discomfort are common presentations. However, hepatitis C is particularly known for being a "silent" infection. Many people with chronic hepatitis C have no symptoms for years or even decades.

Because both infections can be entirely asymptomatic, testing is often the only reliable way to know your status. The absence of symptoms does not mean the absence of infection — and this is especially important when considering hepatitis and sex risk.

Who Should Consider Hepatitis Testing?

There are several situations in which hepatitis testing may be appropriate. You may wish to consider a hepatitis B or hepatitis C test if any of the following apply to you:

• New sexual partner — particularly if you are starting a new relationship and want clarity about your status
• Multiple sexual partners — increased exposure over time raises the statistical chance of encountering the virus
• Unprotected sex — vaginal, anal, or oral sex without a condom increases risk
• Partner diagnosed with hepatitis B or C — testing can determine whether you have been affected
• Travel to high-prevalence areas — parts of Sub-Saharan Africa, East Asia, and the Pacific Islands have higher rates of hepatitis B
• History of needle exposure — including recreational drug use, tattooing, or medical procedures abroad with non-sterile equipment
• Born in a country with high hepatitis B prevalence — some individuals may have been exposed at birth or during childhood

If you are unsure about timing, our guide on how soon after unprotected sex should you get tested provides helpful information about testing windows for various infections, including hepatitis.

Testing does not mean something is definitely wrong. It provides clarity and can be part of a routine approach to looking after your sexual health, similar to STI testing before a new relationship.

How Hepatitis Testing Works in the UK

Hepatitis testing is carried out through a blood test. Unlike some STI tests that use urine or swab samples, hepatitis B and C testing requires a small blood sample, which is sent to a laboratory for analysis.

The blood test typically looks for:

• Hepatitis B surface antigen (HBsAg) — indicates a current hepatitis B infection
• Hepatitis B surface antibody (anti-HBs) — indicates immunity, either from vaccination or previous infection
• Hepatitis B core antibody (anti-HBc) — indicates past or ongoing infection
• Hepatitis C antibody (anti-HCV) — indicates exposure to hepatitis C (a positive result requires confirmatory testing)

Results are handled confidentially, and you will be advised on what they mean and any recommended next steps.

It is worth noting that there is a window period for hepatitis testing. Hepatitis B surface antigen can typically be detected from around 4–6 weeks after exposure, although some guidelines recommend testing at 12 weeks for a more definitive result. Hepatitis C antibodies may take up to 12 weeks to develop, so testing too soon after exposure may produce a false-negative result.

Hepatitis testing may be included as part of a comprehensive STI screen, depending on your risk factors and clinical discussion. Our clinic provides private STI testing but does not provide specialist liver disease management. If results require further evaluation, appropriate signposting to your GP or a hepatology service will be provided.

Hepatitis B Vaccination and Sexual Health

Vaccination plays an important role in sexual health protection. A safe and effective vaccine against hepatitis B is available in the UK and is one of the most reliable ways to protect yourself against infection.

Key facts about the hepatitis B vaccine:

• It is included in the NHS routine childhood immunisation schedule — children born in the UK since 2017 are offered the vaccine as part of the 6-in-1 vaccination programme
• Adults in certain risk groups are eligible for free NHS vaccination — this includes people who inject drugs, sex workers, men who have sex with men, and close contacts of someone with hepatitis B
• Private vaccination is available for those who do not fall into NHS eligibility groups. Your GP or a travel health clinic can advise on access
• The vaccine is typically given in three doses over several months to build full immunity
• It provides strong, long-lasting protection — studies suggest that vaccination provides protection for at least 20 years, and potentially for life, in most people who respond to the vaccine

It is important to note that the hepatitis B vaccine does not treat an existing infection. If you already have hepatitis B, vaccination will not help — but it will protect uninfected partners and contacts.

There is currently no vaccine available for hepatitis C. Prevention of hepatitis C relies on avoiding blood-to-blood contact, practising safer sex, and ensuring that any needles or equipment used for tattoos, piercings, or injections are sterile.

If further medical assessment, vaccination, or treatment is required, you may be advised to consult your GP or appropriate specialist services. If you are unsure whether hepatitis B vaccination may be relevant to your situation, your GP can advise.

Can Hepatitis Clear on Its Own?

The body's response to hepatitis infection varies depending on the virus and the individual:

Hepatitis B:

• In adults, approximately 90–95% of people with acute hepatitis B will clear the virus naturally within six months
• The remaining 5–10% may develop chronic hepatitis B, where the virus persists in the body long-term
• In infants and young children, the risk of developing chronic infection is much higher — up to 90% of babies infected at birth may develop chronic hepatitis B
• Chronic hepatitis B requires specialist monitoring and, in some cases, antiviral treatment

Hepatitis C:

• Acute hepatitis C clears spontaneously in approximately 25–30% of cases
• The majority of people (around 70–75%) will develop chronic hepatitis C if untreated
• However, effective antiviral treatments are now available that can cure hepatitis C in the vast majority of cases — typically with a course of direct-acting antivirals (DAAs) over 8–12 weeks

The possibility of clearing the virus naturally does not remove the value of testing. Knowing your status allows you to make informed decisions about your health and reduces the risk of unknowingly transmitting the infection to others.

Hepatitis, Relationships & Disclosure

Navigating hepatitis within a relationship — whether new or established — can raise questions about communication, testing, and protection.

If you or a partner have been diagnosed with hepatitis B or C, open communication is important. This is not about blame or judgement — it is about making shared, informed decisions to protect one another's health.

Practical steps that may be helpful include:

• Testing before a new relationship — STI testing before a new relationship can provide clarity for both partners and is a responsible approach to sexual health
• Discussing vaccination — if one partner has hepatitis B, the other partner can discuss vaccination with their GP to reduce risk
• Using condoms — consistent condom use reduces the risk of hepatitis B transmission
• Avoiding sharing personal items — razors, toothbrushes, and other items that may carry blood should not be shared

It is also worth knowing that having been successfully treated for an STI in the past does not prevent reinfection with a different infection. Our guide on can you get the same STI twice discusses this topic in more detail.

Hepatitis diagnosis is not a reflection of character. It is a medical condition that can affect anyone, regardless of lifestyle, and approaching it with honesty and care supports both partners.

Frequently Asked Questions

Is hepatitis B an STI?

Hepatitis B can be transmitted through sexual contact and is often included in STI screening panels. While it is not exclusively a sexually transmitted infection — it can also be spread through blood-to-blood contact and from mother to baby — sexual transmission is one of the most common routes in adults. For this reason, it is frequently discussed alongside other STIs.

Can hepatitis C be spread through sex?

Hepatitis C can be spread through sex, although the risk is lower than for hepatitis B. Sexual transmission of hepatitis C is more likely during practices that involve blood exposure or in the presence of other STIs. The risk is higher among MSM populations. For most heterosexual couples, the risk is considered low but not zero.

Should I get tested after unprotected sex?

If you have had unprotected sex with a partner whose hepatitis status is unknown, testing can provide clarity. The timing of testing matters — hepatitis B can typically be detected from around 4–6 weeks after exposure, while hepatitis C antibodies may take up to 12 weeks to appear. Your clinician can advise on the most appropriate testing window.

Does the hepatitis B vaccine last for life?

Evidence suggests that the hepatitis B vaccine provides long-lasting protection — at least 20 years and potentially for life — in the majority of people who respond to the initial vaccination course. Some individuals, particularly those in higher-risk groups, may be advised to have a booster dose. Your GP can check your antibody levels if you are unsure about your vaccination status.

Can you have hepatitis without symptoms?

Yes. Both hepatitis B and hepatitis C can be entirely asymptomatic, particularly in the early stages. Chronic hepatitis C, in particular, is known for producing few or no symptoms for years. This is one of the main reasons why testing is important, especially if you have risk factors for exposure.

Is hepatitis included in standard STI tests?

Hepatitis B and C are not always included in basic STI screening panels. Whether hepatitis testing is included depends on the type of screen selected and your individual risk factors. If you are concerned about hepatitis specifically, mention this when booking your appointment so that appropriate tests can be included.

When to Seek Medical Advice

You should consider seeking prompt medical advice if you experience any of the following:

• Jaundice — yellowing of the skin or the whites of the eyes
• Severe or persistent abdominal pain — particularly in the upper right side
• Persistent fatigue — tiredness that does not improve with rest over several weeks
• Dark urine and pale stools — particularly if combined with other symptoms
• Abnormal blood test results — if liver function tests show elevated readings

If you experience significant symptoms or abnormal liver results, consultation with your GP or specialist services may be advised. These symptoms do not necessarily indicate a serious problem, but they warrant clinical evaluation to ensure that any issues are identified and managed appropriately.

Confidential Hepatitis & STI Testing in the UK

If you are concerned about hepatitis exposure or would like reassurance, confidential STI testing appointments are available at our UK clinic. Testing decisions depend on your symptoms and risk history.

Whether you are wondering can you get hepatitis B from sex, considering testing after a new partner, or simply want peace of mind, testing provides the clearest path to understanding your status. If results indicate that further medical assessment, vaccination, or specialist referral is needed, you will be signposted to your GP or appropriate specialist service.

You may also find our blog post on sex after STI treatment helpful. Book a confidential testing appointment at a time that suits you.