Disclosure: SunnyPharma.info does not sell medication. This page is for informational purposes only and does not constitute medical advice. Always consult a qualified HIV care provider before making treatment decisions.
Dr. Ranjit Mohan, MD
Medical Reviewer
Richard Boehme
Medical Writer
Antiretroviral therapy (ART) is the standard of care for HIV infection worldwide. It consists of a combination of antiretroviral drugs that suppress HIV replication to undetectable levels — halting disease progression, restoring immune function, and eliminating the risk of sexual transmission. Since the introduction of combination therapy in 1996, ART has transformed HIV from a disease with a prognosis measured in years to one managed as a lifelong chronic condition with near-normal life expectancy for those who start treatment early.
How Antiretroviral Therapy Works
HIV replicates by hijacking human CD4 T-cells. The virus binds to the cell surface, enters the cell, converts its RNA genome into DNA using reverse transcriptase, integrates that DNA into the host cell’s genome using integrase, and then uses the cell’s machinery to produce new viral particles that go on to infect other cells. ART works by blocking one or more of these steps simultaneously — making it impossible for the virus to complete its replication cycle.
The Seven Classes of Antiretroviral Drugs
The FDA has approved antiretroviral drugs across seven mechanistic classes. Modern treatment regimens typically combine two or three agents from different classes to achieve viral suppression while minimising resistance risk.
Preferred First-Line Regimens in 2026
The US DHHS guidelines and WHO both recommend integrase inhibitor-based regimens as preferred first-line therapy for treatment-naive adults with HIV. The selection of a specific regimen depends on factors including viral load at baseline, renal function, co-medications, co-morbidities, and patient preference.
| Regimen | Components | Format | Key Advantage |
|---|---|---|---|
| Biktarvy | BIC + FTC + TAF | 1 pill / day | Highest barrier to resistance of any STR; >98% suppression at 5 years; no food requirement |
| Dovato | DTG + 3TC | 1 pill / day | 2-drug regimen reduces long-term drug exposure; suitable for patients with renal or bone concerns; requires baseline resistance testing |
| Symtuza | DRV/COBI + FTC + TAF | 1 pill / day | PI-based option with high genetic barrier; useful when INSTI resistance is suspected; requires food |
| Cabenuva | CAB + RPV (injectable) | Monthly or bimonthly injection | Eliminates daily pill burden; preferred for patients with adherence challenges; requires achieving viral suppression on oral regimen first |
| Sunlenca + darunavir | Lenacapavir + DRV/COBI | Twice-yearly injection | Longest-acting regimen available; currently approved for treatment-experienced patients with multi-drug resistant HIV |
For a detailed look at how Biktarvy works, what it treats, and its clinical trial data, see what Biktarvy is used for. For the full cost picture across regimens, see the HIV treatment cost guide.
When to Start Antiretroviral Therapy
Current guidelines from the DHHS, WHO, and BHIVA all recommend starting ART as soon as possible after HIV diagnosis, regardless of CD4 count. This represents a shift from earlier guidance that recommended deferring treatment until CD4 counts fell below certain thresholds.
The evidence base for immediate initiation comes primarily from the INSIGHT START trial (2015), which demonstrated that patients randomised to immediate ART had significantly fewer serious illness events and deaths than those in the deferred arm — even when the deferred group had CD4 counts above 500 cells/µL at enrolment.
Clinical principle: The single most important determinant of long-term prognosis in HIV is the CD4 count at which treatment is started. Starting ART before significant immune damage — ideally above 500 cells/µL — is associated with life expectancy approaching that of HIV-negative peers on current evidence. Every month of delay after diagnosis carries a cost in immune function that may not be fully recovered even after years of successful viral suppression.
Adherence: Why It Matters More Than Which Drug You Take
The choice between Biktarvy and Dovato, for most treatment-naive patients, matters far less than whether the chosen regimen is taken consistently. Adherence — taking the medication every day without significant gaps — is the dominant determinant of treatment success in clinical practice.
Adherence matters for two reasons. First, inconsistent drug levels allow HIV to replicate in the presence of sub-therapeutic concentrations of antiretrovirals — the conditions under which resistance mutations are selected. Second, viral rebound from treatment gaps allows ongoing immune damage and restores transmission risk.
- High-barrier regimens like Biktarvy are more forgiving of occasional missed doses than older low-barrier drugs, but this does not mean adherence is unimportant.
- Long-acting injectable regimens like Cabenuva were developed specifically for patients who struggle with daily oral adherence. Monthly or bimonthly clinic attendance for injection is a different adherence challenge — one that some patients find easier and others more difficult.
- Adherence support — including reminder systems, patient education, and addressing underlying barriers like depression, substance use, or housing instability — is as clinically important as drug selection.
Side Effects and Long-Term Tolerability
Modern INSTI-based regimens are substantially better tolerated than earlier ART generations. The most common side effects with Biktarvy and similar regimens are gastrointestinal (nausea, diarrhoea) and occur primarily in the first few weeks of treatment in a minority of patients. Serious side effects requiring treatment discontinuation occurred in under 1% of patients in 5-year clinical trial data.
Longer-term considerations include modest effects on weight, kidney function markers, and bone mineral density — all of which require monitoring but rarely require treatment change. For a detailed review of what the evidence shows on each of these over five years, see the Biktarvy long-term side effects page. For a full guide to side effects in the first weeks through to years of treatment, see the Biktarvy side effects page.
Drug interactions: Antiretroviral drugs — particularly those boosted with cobicistat or ritonavir, and INSTIs — have important interactions with common medications. Antacids and supplements containing divalent cations (calcium, magnesium, iron, zinc) must be separated from INSTI-based regimens by at least two hours. For a comprehensive drug interaction reference, see Biktarvy drug interactions.
Frequently Asked Questions
Antiretroviral therapy (ART) is the combination drug treatment used to suppress HIV replication. HIV replicates by entering CD4 immune cells and using the cell’s machinery to produce copies of itself. ART works by blocking one or more essential steps in this replication cycle — reverse transcription, integration, protein maturation, or cell entry — using drugs from different mechanistic classes simultaneously. Using multiple classes at once makes it extremely difficult for HIV to mutate its way around treatment, which is why combination therapy is so much more effective than the single-drug monotherapy used in the early 1990s.
HAART — Highly Active Antiretroviral Therapy — was the term used from the mid-1990s through to the early 2010s to describe combination antiretroviral regimens. It distinguished the powerful combination approach from earlier ineffective monotherapy. The term ART (antiretroviral therapy) has largely replaced HAART in current clinical and scientific usage, as modern therapy is considered standard care rather than a specially designated “highly active” approach. The underlying concept — combining drugs from multiple classes to prevent viral resistance — is the same.
No — ART suppresses HIV to undetectable levels but does not eliminate it from the body. HIV integrates into the DNA of long-lived resting CD4 T-cells, forming a latent reservoir that persists even during fully suppressive ART. Stopping treatment allows the virus to rebound from this reservoir, typically within weeks. This is why ART must be taken for life with current treatment options.
For most treatment-naive adults, DHHS preferred first-line regimens in 2026 are Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) or Dovato (dolutegravir/lamivudine). Biktarvy offers the highest resistance barrier of any single-tablet regimen and has no food requirement or baseline resistance testing requirement. Dovato offers a 2-drug option with less long-term drug exposure, but requires baseline resistance testing and is not suitable for patients with hepatitis B co-infection. The best regimen for any individual depends on their specific clinical situation.
Viral load begins to fall within days of starting ART. Most patients on modern INSTI-based regimens achieve an undetectable viral load (below 50 copies/mL) within 4–12 weeks of starting treatment. The standard monitoring schedule checks viral load at 4 weeks, then at 12 weeks, then every 3–6 months thereafter. CD4 count recovery is slower — significant immune reconstitution typically takes 3–12 months and may continue for several years, particularly in patients who started with very low CD4 counts.
Drug resistance occurs when HIV replicates in the presence of sub-therapeutic drug concentrations — typically due to missed doses — and selects for mutations that reduce drug susceptibility. Modern INSTI-based regimens, particularly those containing bictegravir or dolutegravir, have a high genetic barrier to resistance, meaning multiple simultaneous mutations would need to occur for resistance to develop — which is rare with adequate adherence.
References
- DHHS Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the Use of Antiretroviral Agents. Updated January 2025. clinicalinfo.hiv.gov.
- INSIGHT START Study Group. Initiation of Antiretroviral Therapy in Early Asymptomatic HIV Infection. N Engl J Med. 2015;373(9):795–807.
- Gallant J et al. Bictegravir, emtricitabine, and tenofovir alafenamide versus dolutegravir, abacavir, and lamivudine for initial treatment of HIV-1 infection. Lancet. 2017;390(10107):2063–2072.
- WHO. Consolidated Guidelines on HIV Prevention, Testing, Treatment, Service Delivery and Monitoring. 2021. who.int.
- Rodger AJ et al. Risk of HIV transmission through condomless sex in serodifferent gay couples (PARTNER). Lancet. 2019;393(10189):2428–2438.
- Flexner C. HIV drug development: the next 25 years. Nat Rev Drug Discov. 2007;6(12):959–966.