PrEP – PreExposure Prophylaxis to prevent HIV Infection
PreExposure Prophylaxis is a way to prevent contracting HIV. The procedure involves putting a healthy person under medication few days before he/she involves in risky sexual behaviour or abuse drugs possibly by sharing needles.
Who are the right people to take PrEP / When should you consider PrEP ?
- People who abuse drugs and share needles to inject drugs.
- People who are sexually active and prefer to have unprotected sex with new partners
- Gay men who prefer to have unsafe sex
- People who have sex with strangers, one night stand after getting drunk (under the influence of alcohol).
- People who were diagnosed with any STD during the last 6 months.
If you are one among any of those people, you may consider opting PrEP after consulting a sexologist. Read on to know more about PrEP.
What are the different types of PrEP?
There are two different types of PrEP medicines available:
- One is prescribed for people who have unprotected sex or abuse drugs with shared needles. (Truvada ®)
- The other one is for people who have unprotected sex but not for women. (Descovy ®)

What are the side effects of PrEP medication?
Your sexologist will explain to you what you can expect once you start the medication. Some side effects include diarrhoea, nausea, headache, stomach pain, fatigue. These side effects may from patient to patient depending on the tolerance levels of their bodies to the medicine.
Once the body gets used to the medicines, the side effects should go away. If they don’t go away, you must get back to your doctor immediately.
Can PrEP stop a person from contracting HIV?
The answer to this question is a Yes and No because PrEP does not guarantee 100% protection against getting infected with HIV but it reduces the chances by as much as 99% provided the medicine is taken as prescribed by your sex specialist. If not, it cannot protect as expected.
- PrEP protects a person from getting HIV infection through sex by 99%
- PrEP protects a person from getting HIV by only 74% who use shared needles to inject drugs etc.
It is important to abstain from risky behaviour for few days once the person starts PrEP treatment.
- A minimum window of 7 days is needed for PrEP medicine to take effect and start protecting men who indulge in gay sex (especially on the receiving side in anal sex).
- A minimum window of 21 days is needed in people who involve in unprotected penetrative sexual acts (heterosexual) or share needles.
PrEP medication can fail if not taken as per prescription or if the window period is not followed. If you happen to ignore the window period and if you think that you might be at risk of contracting HIV, you must see your doctor immediately. He/she may perform certain STD Tests and put you on Post Exposure Prophylaxis therapy.
Starting and Stopping PrEP
Before putting a person onto PrEP, his/her doctor will get him/her tested for HIV. Only in case of a negative report, the treatment will be started. Should the person test positive, treatment will take a different route by putting him/her on Anti Retroviral medicines.
Once PrEP is started, the person has to visit the doctor and get tested for HIV. In most of the cases, the person should test negative.
If the person wants to stop PrEP due to change in his/her thinking, lifestyle, relationship status or because of side effects etc, he/she can surely talk to his/her doctor for alternatives options.
On demand PrEP
Instead of continued medication, can a person take PrEP medication on demand ie, only when he/she thinks that she/he may be going to have unprotected sex or share needles with a stranger?
Yes, the procedure is called ‘intermittent’, ‘non-daily’, ‘event-driven’ or ‘Off-label’ use of PrEP. In this scenario, the person will have to take medication 2-24 hours before the act, again after 24 hours of first dose and then one more dose after 24 hours of second dose. As per study, on demand PrEP has shown to be effective in gay and bisexual men who involve in anal sex. However, there is very little evidence that on demand PrEP will offer protection for heterosexual men and women.
The best way to stay safe and not contract HIV is abstinence or not having sex with a stranger/unfamiliar person or someone who is not your long time partner. In case such a situation should arise, one must use a male/female condom or a dental dam. If you had unprotected sex with someone who you don’t really don’t know, please see a good sexologist as soon as possible, preferably within 72 hours of the act so that your doctor can put you on PEP.