PEP vs PrEP — What's the Difference?
Both are HIV prevention tools — but they serve completely different situations. Understanding the difference could be critical to your health.
PEP — Emergency (AFTER exposure)
Post-Exposure Prophylaxis. Used AFTER a single, specific potential HIV exposure. This is an emergency treatment with a strict 72-hour window — every hour counts.
- •Taken for 28–30 days after exposure
- •Must start within 72 hours (ideally within 2 hours)
- •Up to 98% effective when started early
- •For one-time or infrequent exposures
- •Consultation fee: ₹2,000 + medicine cost
PrEP — Prevention (BEFORE exposure)
Pre-Exposure Prophylaxis. Used BEFORE potential exposures by HIV-negative individuals who are at ongoing or recurring risk. This is a preventive strategy, not an emergency treatment.
- •Taken daily (or on-demand for some regimens)
- •Provides ongoing, continuous protection
- •Over 99% effective when taken consistently
- •For recurring or consistent HIV risk
- •Requires periodic follow-up and monitoring
When to Use PEP vs PrEP — A Clinical Guide
The choice between PEP and PrEP depends entirely on your situation and timing. Both are prescribed by a specialist after proper assessment.
Use PEP if you have just had a potential HIV exposure
PEP is indicated when a specific, identifiable potential HIV exposure has occurred within the last 72 hours. Examples include: unprotected sex with a new or unknown-status partner, condom failure, needle-stick or sharp injury, or sex worker contact. If this applies to you and you are within 72 hours, call immediately — the effectiveness of PEP decreases with every hour of delay, and there is no clinical benefit to starting after 72 hours have passed.
Use PrEP if you are at ongoing, recurring risk
PrEP is appropriate for HIV-negative individuals who have recurring potential exposures. This includes people with multiple sexual partners, serodiscordant couples (where one partner is HIV-positive), people who use intravenous drugs, and sex workers. PrEP is not an emergency drug — it needs to reach protective levels in the body before exposure occurs, which takes a few days of consistent dosing.
Transitioning from PEP to PrEP
If you have needed PEP multiple times, or if the risk factors that led to this exposure are likely to recur, Dr. Monga will discuss transitioning to PrEP after your PEP course is complete and a confirmatory HIV test at 4–6 weeks is negative. This is a common and clinically appropriate pathway for patients whose risk profile warrants ongoing prevention.
Key Differences Summary
| Feature | PEP | PrEP |
|---|---|---|
| Timing | AFTER exposure | BEFORE exposure |
| Use case | Single emergency event | Ongoing/recurring risk |
| Duration | 28–30 days (fixed) | Continuous (ongoing) |
| 72-hour window? | Yes — strict limit | No — taken in advance |
| Effectiveness (when used correctly) | Up to 98% (when started early) | Over 99% |
| HIV test required before starting? | Yes (baseline) | Yes (to confirm HIV-negative) |
| Monitoring needed? | Follow-up test at 4–6 weeks and 3 months | Every 3 months (HIV test + kidney function) |
Can PEP or PrEP be obtained without a prescription in India?
Legally, both PEP and PrEP medicines require a prescription from a qualified doctor. More importantly, starting either without medical assessment is inadvisable: regimen selection, timing, drug interactions, and baseline testing all require specialist involvement. Self-prescribing without clinical guidance introduces significant risk of suboptimal dosing, missed interactions, and — in the case of PEP — incorrect timing that may make the course ineffective.
Cost Comparison in India (2025)
PEP: Consultation ₹2,000 + medicine cost ₹2,500–₹12,000 for a 28-day course (depending on regimen and brand vs. generic).
PrEP: Consultation ₹2,000 + monthly medicine cost (generic TDF/FTC approximately ₹800–₹1,500/month; branded options higher). Follow-up consultations every 3 months recommended.
Unsure whether you need PEP or PrEP? Book a confidential consultation with Dr. Monga for a proper assessment.
Confidential, specialist-level care — 100% discreet.