What is PrEP?

PrEP is HIV prevention medicine for people without HIV. Get to know every form — daily oral, on-demand, and the new long-acting injectables — with the latest status in Thailand.

What PrEP is

PrEP stands for pre-exposure prophylaxis. It is the use of antiretroviral medicine by people who do not have HIV to prevent infection.

How PrEP works

When there is enough medicine in the body, it helps stop HIV from taking hold and multiplying if you are exposed, greatly lowering the chance of infection.

Who PrEP is for

PrEP is for people who do not have HIV but are at risk of getting it, such as those with a partner who has HIV or who often have sex without condoms. See the full prevention overview at HIV prevention: all your options.

PrEP is one part of prevention

PrEP is a powerful prevention tool, but it works best alongside other methods such as condoms and regular testing. Seeing the whole picture helps you choose the protection that fits you.

How well PrEP works

PrEP is a highly effective way to prevent HIV when used correctly.

Effectiveness depends on consistency

When PrEP is used consistently as directed, it lowers the risk of getting HIV sexually almost entirely. The key is staying on it so the drug level in the body is high enough.

Why injectable PrEP is exciting

One challenge with oral PrEP is taking a pill every day. Long-acting injectable PrEP is an option that helps with this, because there is no daily pill, as explained in the sections below.

The types of PrEP

PrEP now comes in several forms, from pills to long-acting injections.

The forms of PrEP

• Daily oral PrEP — a pill taken once a day, the most widely used form
• On-demand PrEP (2-1-1) — taken only around a period of risk, for some groups
• Injectable cabotegravir — an injection every 2 months
• Injectable lenacapavir — an injection twice a year, the newest option

Choose what fits you

Each has its own advantages: some people find a pill convenient, while others prefer an injection with nothing to remember daily. The next sections explain each one in detail.

Daily oral PrEP

Daily oral PrEP is the most widely used form and is part of Thailand's national PrEP programme.

How to use it

Take one pill a day at around the same time so the drug level stays steady. The medicine is usually a combination antiretroviral that is available as a generic, which makes it accessible.

The advantages

• long established, with a large body of evidence
• easy to access and affordable in Thailand
• can be stopped or restarted on a clinician's advice

The key is taking it consistently, because its effectiveness depends on having enough of the drug in the body.

Who it suits

Oral PrEP suits people who are comfortable taking a daily pill and want a well-established option, and it is also easy to adjust if your risk changes.

On-demand PrEP (2-1-1)

On-demand PrEP, or 2-1-1, means taking PrEP only around an expected period of risk.

How to take it

The 2-1-1 schedule is two pills 2 to 24 hours before sex, then one pill 24 hours later, and one more pill 24 hours after that.

Who it suits

On-demand PrEP suits some groups whose risk is occasional rather than ongoing, and it comes with specific guidance on its use, so talk to a provider first. Read the detail at on-demand PrEP.

Injectable PrEP: cabotegravir (CAB-LA)

The first injectable PrEP available in Thailand is long-acting cabotegravir (CAB-LA), known by the brand name Apretude.

An injection every 2 months

After a starting phase, CAB-LA is given every 2 months, so there is no daily pill. It suits people who find daily dosing hard or who want privacy.

Its status in Thailand

CAB-LA is approved and has been available in Thailand since early 2025 through registered services, such as the Thai Red Cross AIDS Research Centre and some community clinics. Studies found that the injection improves protection, partly by solving the problem of inconsistent daily dosing.

What to know

CAB-LA is not a vaccine — it must be given on schedule, and missing or delaying a dose can raise the risk, so plan your injections with your provider.

The advantage of the every-2-months injection

The main advantage of CAB-LA is that there is no daily pill, which eases the burden of remembering and adds privacy. Studies abroad found that the injection led to more consistent protection in many cases.

Injectable PrEP: lenacapavir (twice a year)

The newest option is injectable lenacapavir (LEN), a PrEP that is given just twice a year.

An injection every 6 months

Lenacapavir is injected under the skin every 6 months — only twice a year — making it the longest-acting PrEP available today. It is very convenient for people who find frequent clinic visits difficult.

Very high efficacy

Lenacapavir was approved by the FDA in June 2025 and recommended by the World Health Organization in July 2025, based on the PURPOSE 1 and PURPOSE 2 studies, which found very high protection, with almost no infections in the groups that received it.

Its status in Thailand

In Thailand, lenacapavir for PrEP is in the process of being introduced — in late 2025, funding was approved for a pilot programme of twice-yearly lenacapavir, and wider access is expected in the future. Because this is changing quickly, check the latest availability with a clinic or through Love2Test.

Why lenacapavir is drawing attention

Needing only two injections a year eases the problems of forgetting pills and frequent clinic visits, which have been major barriers to PrEP. Many see it as an important step for HIV prevention worldwide.

Who should use PrEP

PrEP is not needed by everyone, but it suits people at risk of getting HIV.

Consider PrEP if you

• have a partner with HIV, especially one who is still detectable
• have sex without condoms with people whose status you do not know
• have several partners
• have used PEP often
• share injecting equipment

Assess it with a provider

The decision to use PrEP is best made with a health provider who can assess your risk and help choose the right form. Read the detail at who should take PrEP.

Side effects and safety

PrEP is safe for most people, but there are a few things to know about side effects.

Possible side effects

• Oral — some people have mild effects early on, such as nausea or headache, which usually settle on their own
• Injectable — the most common side effect is an injection-site reaction, such as mild soreness or swelling, which is usually not serious

Health monitoring

People on PrEP should have regular HIV tests and check-ups for safety and follow-up. Read the detail on side effects at PrEP side effects.

Starting PrEP and where to get it

Starting PrEP involves a few important steps for safety and effectiveness.

Before starting

• you must test for HIV first and be negative, because PrEP is for people who do not have HIV
• there are baseline checks, such as kidney function, and testing for other STIs

Where to get PrEP

PrEP is available at hospitals, specialist clinics, and many community organisations in Thailand, both oral and injectable depending on each service. See services at where to get PrEP, or find and book a clinic at Love2Test.

What PrEP does not protect against

Although PrEP is very good at preventing HIV, it has an important limit to understand.

PrEP only protects against HIV

PrEP does not protect against other sexually transmitted infections, such as syphilis, gonorrhoea, or herpes, and it does not prevent pregnancy.

So use it with condoms

Using condoms together with PrEP gives more complete protection — against HIV, other STIs, and pregnancy. Regular sexual-health check-ups are important too.

Well-rounded protection

The best protection is usually a combination: PrEP covers HIV, condoms cover other STIs and pregnancy, and regular testing keeps you and your partner informed.

In summary

PrEP is antiretroviral medicine used by people without HIV to prevent it, and it is highly effective when used consistently. It now comes in several forms — daily oral, on-demand, and long-acting injectables: cabotegravir every 2 months and lenacapavir twice a year.

Injectable PrEP is an advance that helps with the challenge of daily pills. CAB-LA is already available in Thailand at registered services, while lenacapavir is being introduced. Still, PrEP only protects against HIV, so use it with condoms for more complete protection.

If you want to start PrEP or ask about the latest availability of the injectable options, find and book a clinic at Love2Test.