What the label lists and what reports show
Cobicistat and darunavir side effects
Cobicistat and darunavir's FDA label: “The most common adverse reactions to darunavir, a component of PREZCOBIX or PREZCOBIX PED (incidence greater than or equal to 5%) of at least moderate severity (greater than or equal to Grade 2) were diarrhea, nausea, rash, headache, abdominal pain, and …” FAERS holds 1,754 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is pain (440 reports).
- No generic listed
Check it at the source: the cobicistat and darunavir FDA label on DailyMed (effective February 1, 2026, Janssen Products, LP); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of PREZCOBIX or PREZCOBIX PED?PREZCOBIX or PREZCOBIX PED may cause serious side effects, including: See " What is the most important information I should know about PREZCOBIX or PREZCOBIX PED? " Diabetes and high blood sugar (hyperglycemia). New or worsening diabetes and hyperglycemia have happened in people who take protease inhibitors including PREZCOBIX or PREZCOBIX PED. Some people have had to start taking medicine to treat diabetes or have had to change their diabetes medicine. Tell your healthcare provider if you notice an increase in thirst or if you start urinating more often during treatment with PREZCOBIX or PREZCOBIX PED. Changes in body fat can happen in people who take HIV-1 medicine. The changes may include an increased amount of fat in the upper back and neck ("buffalo hump"), breast, and around the middle of your body (trunk). Loss of fat from the legs, arms, and face may also happen. […]
Source: FDA drug label, Janssen Products, LP, effective February 1, 2026 (SPL set 9c38fdb6-d0ba-4f16-a0e3-85d9ec334d9f), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions to darunavir, a component of PREZCOBIX or PREZCOBIX PED (incidence greater than or equal to 5%) of at least moderate severity (greater than or equal to Grade 2) were diarrhea, nausea, rash, headache, abdominal pain, and vomiting.
From the label: adverse reactions, continuedThe following adverse reactions are discussed in other sections of the labeling: Hepatotoxicity [see Warnings and Precautions (5.1) ] Severe skin reactions [see Warnings and Precautions (5.2) ] Effects on serum creatinine [see Warnings and Precautions (5.3) ] New onset or worsening renal impairment when used with tenofovir DF [see Warnings and Precautions (5.4) ] Immune Reconstitution Syndrome [see Warnings and Precautions (5.10) ] The most common adverse reactions to darunavir, a component of PREZCOBIX or PREZCOBIX PED (incidence greater than or equal to 5%) of at least moderate severity (greater than or equal to Grade 2) were diarrhea, nausea, rash, headache, abdominal pain, and vomiting. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Janssen Products, LP at 1-800-JANSSEN (1-800-526-7736) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. …
Source: FDA drug label, Janssen Products, LP, effective February 1, 2026 (SPL set 9c38fdb6-d0ba-4f16-a0e3-85d9ec334d9f), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,754 reports list cobicistat and darunavir among the medicines taken, each a report of something that happened, not proof the medicine caused it; 135 are coded as a death and 397 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 22 reactions below, 4 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Cobicistat and darunavir: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions