Onexton Side Effects Center

Last updated on RxList: 5/5/2022
Onexton Side Effects Center

What Is Onexton?

Onexton (clindamycin phosphate and benzoyl peroxide) Gel is a combination of an antibiotic and an antibacterial and keratolytic agent indicated for the topical treatment of acne vulgaris in patients 12 years of age and older.

What Are Side Effects of Onexton?

Common side effects of Onexton include:

  • burning or stinging sensation,
  • skin irritation (contact dermatitis),
  • itching,
  • rash,
  • dryness,
  • peeling, or
  • redness of skin

Dosage for Onexton

Before applying Onexton Gel, wash the face gently with a mild soap, rinse with warm water, and pat the skin dry. Apply a pea-sized dose amount of Onexton Gel to the face once daily.

What Drugs, Substances, or Supplements Interact with Onexton?

Onexton may interact with topical or oral erythromycin, other topical acne therapy used at the same time, and neuromuscular blocking agents. Tell your doctor all medications and supplements you use.

Onexton During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before using Onexton. It is unknown if Onexton passes into breast milk. Orally and parenterally administered clindamycin passes in breast milk. Because of the potential for serious adverse reactions in nursing infants, Onexton is not recommended for use while breastfeeding; consult your doctor.

Additional Information

Our Onexton (clindamycin phosphate and benzoyl peroxide) Gel Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Skin Health: 15 Tips for Clear Skin See Slideshow
Onexton Consumer Information

Benzoyl peroxide can cause a rare but serious allergic reaction or severe skin irritation. These reactions may occur just a few minutes after you apply the medicine, or within a day or longer afterward.

Stop using this medicine and get emergency medical help if you have signs of an allergic reaction: hives, itching; difficult breathing, feeling light-headed; swelling of your face, lips, tongue, or throat.

Stop using this medicine and call your doctor at once if you have:

  • severe redness, burning, stinging, or peeling of treated skin areas; or
  • diarrhea that is watery or bloody.

Common side effects may include:

  • mild burning or stinging;
  • itching or tingly feeling;
  • dryness or peeling of treated skin; or
  • redness or other irritation.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Acne is the result of an allergy. See Answer
Onexton Professional Information


The following adverse reaction is described in more detail in the WARNINGS AND PRECAUTIONS section of the label:

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of a drug cannot be directly compared to rates observed in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

These adverse reactions occurred in less than 0.5% of subjects treated with ONEXTON Gel: burning sensation (0.4%); contact dermatitis (0.4%); pruritus (0.4%); and rash (0.4%).

During the clinical trial, subjects were assessed for local cutaneous signs and symptoms of erythema, scaling, itching, burning and stinging. Most local skin reactions either were the same as baseline or increased and peaked around week 4 and were near or improved from baseline levels by week 12. The percentage of subjects that had symptoms present before treatment (at baseline), during treatment, and the percent with symptoms present at week 12 are shown in Table 1.

Table 1: Local Skin Reactions -Percent of Subjects with Symptoms Present. Results from the Phase 3 Trial of ONEXTON Gel 1.2%/3.75% (N = 243)

  Before Treatment (Baseline) During Treatment End of Treatment (Week 12)
Mild Mod.* Severe Mild Mod.* Severe Mild Mod.* Severe
Erythema 20 6 0 28 5 < 1 15 2 0
Scaling 10 1 0 19 3 0 10 < 1 0
Itching 14 3 < 1 15 3 0 7 2 0
Burning 5 < 1 < 1 7 1 < 1 3 < 1 0
Stinging 5 < 1 0 7 0 < 1 3 0 < 1
*Mod. = Moderate

Postmarketing Experience

Because postmarketing adverse reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Anaphylaxis, as well as allergic reactions leading to hospitalizations, has been reported in postmarketing use of products containing clindamycin phosphate/benzoyl peroxide.

Read the entire FDA prescribing information for Onexton (Cindamycin Phosphate and Benzoyl Peroxide Gel, 1.2%/3.75)

© Onexton Patient Information is supplied by Cerner Multum, Inc. and Onexton Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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