Quick Answer: Finacea (azelaic acid 15% gel) is labeled for the inflammatory papules and pustules of mild to moderate rosacea, applied twice daily; the label says to reassess if there is no improvement after 12 weeks. MetroGel (metronidazole 1% gel) is labeled for inflammatory lesions of rosacea, applied once daily. In a 15-week randomized trial (Elewski 2003), azelaic acid 15% gel reduced inflammatory lesions more than metronidazole 0.75% gel (72.7% vs 55.8%) and improved redness in more patients. Azelaic acid more often causes burning or stinging early on. Both require a prescription in the US.
Azelaic Acid vs Metronidazole at a Glance
| Feature | Azelaic acid 15% gel (Finacea) | Metronidazole 1% gel (MetroGel) |
|---|---|---|
| Labeled use | Inflammatory papules and pustules of mild to moderate rosacea | Inflammatory lesions of rosacea |
| How applied (label) | Thin layer, twice daily | Thin film, once daily |
| Drug class | Dicarboxylic acid | Nitroimidazole antimicrobial |
| Head-to-head trial (15 wk) | 72.7% lesion reduction | 55.8% (0.75% gel, twice daily) |
| Common local effects | Burning, stinging, itching early in treatment | Mild skin irritation |
| Label notes | Watch for skin-color changes (hypopigmentation) | Avoid eyes; peripheral neuropathy reported post-marketing |
| Status | Rx (lower-strength azelaic cosmetics exist) | Rx |
Doses above are from the current U.S. Drug Facts or prescribing labels listed in Sources. Always follow the label on the package you buy, because store brands and formulations differ.
About Rosacea Bumps
Rosacea is a chronic skin condition that causes facial redness, flushing, visible blood vessels and, in the papulopustular type, acne-like red bumps (papules) and pus bumps (pustules). Unlike acne, there are usually no blackheads. Both azelaic acid and metronidazole are labeled to treat the inflammatory bumps. Neither label claims to treat persistent redness on its own: the Finacea label notes that efficacy for redness in the absence of papules and pustules has not been evaluated.
How They Work
Azelaic acid is a naturally occurring dicarboxylic acid with anti-inflammatory, antimicrobial and keratin-normalizing effects. It is also used for acne and for dark spots; see azelaic acid vs niacinamide and tranexamic acid vs azelaic acid. Metronidazole is an antimicrobial in the nitroimidazole class; in rosacea its benefit is thought to come mostly from anti-inflammatory effects rather than killing bacteria.
Head-to-Head Evidence
Elewski and colleagues (Archives of Dermatology, 2003) randomized adults with papulopustular rosacea to azelaic acid 15% gel or metronidazole 0.75% gel, each twice daily for 15 weeks. Azelaic acid was superior in reducing the mean number of inflammatory lesions (−12.9 vs −10.7) and the mean percent decrease (−72.7% vs −55.8%). For redness, 56% of azelaic acid patients were rated improved versus 42% with metronidazole. The authors reported that metronidazole’s effect seemed to plateau after week 8, whereas azelaic acid continued to improve. The trial compared the 0.75% metronidazole gel, not the 1% once-daily MetroGel.
How Each Is Used
Finacea (azelaic acid 15% gel)
- Gently massage a thin layer into the affected areas of the face twice daily, morning and evening.
- Reassess with your prescriber if there is no improvement after 12 weeks.
- Burning, stinging or itching may occur, usually in the first few weeks. If irritation is excessive or persists, stop and contact your clinician.
- Avoid the eyes and occlusive dressings. The label notes rare reports of lighter skin color (hypopigmentation) and advises monitoring people with darker complexions.
MetroGel (metronidazole 1% gel)
- Cleanse the area with a gentle cleanser, then apply and rub in a thin film once daily. Cosmetics may be applied afterward.
- Not for oral, eye or vaginal use.
- Reported effects include skin irritation and transient redness; peripheral neuropathy has been reported after approval. Tell your clinician about numbness or tingling.
- The MetroGel label notes it is Pregnancy Category B, with no adequate studies in pregnant women; ask your clinician.
Daily Habits That Help
The Finacea label advises patients to avoid foods and drinks that provoke flushing, including spicy foods, alcohol and hot drinks such as hot coffee and tea, and to use only very mild soaps or soapless cleansers. Daily broad-spectrum sunscreen and gentle, fragrance-free skin care are commonly recommended for rosacea.
How Clinicians Decide
- Dosing preference: once-daily MetroGel vs twice-daily Finacea.
- Sensitive skin: azelaic acid more often stings early on.
- Coexisting concerns: azelaic acid also targets acne and uneven pigmentation.
- Other options: ivermectin cream, oral doxycycline and topicals for persistent redness are discussed with a dermatologist.
Putting It Together: Common Situations
The scenarios below summarize what the labels and guidelines cited on this page say. They are general information, not a personal treatment plan. Your pharmacist can check the choice against your other medicines, and your clinician can tailor it to your health history.
- Prefer once-daily dosing: MetroGel 1% is labeled once daily.
- Bumps and pustules not improving: in the Elewski trial, azelaic acid continued to improve after week 8.
- Stinging-prone skin: the Finacea label notes burning or stinging early in treatment.
How to Read the Label Before You Buy
- Find the active ingredient first. Brand names are often reused across products with different ingredients. The active ingredient and its strength appear at the top of the Drug Facts or Supplement Facts panel.
- Check the “Uses” or labeled indication. A product is tested and labeled for specific uses. Using it for something else may not help.
- Read the “Do not use” and “Ask a doctor before use” sections. They list conditions and medicines where the product may be unsafe.
- Follow the directions for dose and duration. Note the maximum daily amount and how many days you can use it before checking with a clinician.
- Check for duplicate ingredients. Combination products can contain the same ingredient as something else you take, which raises the risk of taking too much.
- Note the “Stop use and ask a doctor” signs. These are the label’s own warning signs that a product is not working or is causing harm.
Common Mistakes to Avoid
- Expecting either gel to remove persistent redness alone. Both are labeled for inflammatory lesions.
- Ignoring flushing triggers, which the Finacea label lists as spicy food, alcohol and hot drinks.
- Assuming two products with similar names are interchangeable. Compare the active ingredients and strengths instead of the packaging.
- Forgetting to tell your clinician. Keep a current list of every prescription, OTC medicine and supplement you take, and bring it to appointments and the pharmacy.
FormulaCompare does not recommend one brand over another. Use the sources below to check the details for the exact product in front of you, since formulas and labels can change.
Putting the Trial in Context
The Elewski trial is a single head-to-head study, and it used metronidazole 0.75% gel twice daily, while MetroGel 1% is labeled for once-daily use. Results from one trial may not apply to every patient or formulation. Both drugs are FDA-approved for rosacea bumps, and both have been used for many years. In everyday practice, dermatologists weigh how sensitive the skin is, how many bumps are present, whether there is acne or pigmentation as well, and which schedule a person will stick with. Many people need several weeks before judging results, and the Finacea label sets 12 weeks as the point to reassess.
Fitting a Rosacea Gel Into a Routine
Cleanse with a mild, soapless cleanser and pat dry. Apply the prescribed gel as a thin layer to the affected areas only as often as the label directs. Wait for it to absorb before applying moisturizer or makeup; the MetroGel label notes cosmetics may be applied after it. In the morning, finish with a broad-spectrum sunscreen. Keep a simple diary of flushing triggers so you can discuss patterns with your dermatologist.
When to Talk to Your Doctor or Pharmacist
See a dermatologist to confirm rosacea, especially if you have eye symptoms such as burning, grittiness or light sensitivity, thickened skin on the nose, or bumps that do not respond to treatment after about 12 weeks. Stop a product and call your clinician for severe irritation, swelling or numbness and tingling.
Frequently Asked Questions
Is azelaic acid better than metronidazole for rosacea?
In one 15-week trial, azelaic acid 15% gel reduced lesions more than metronidazole 0.75% gel. Individual results vary, and your dermatologist may choose either.
Do they treat rosacea redness?
Both are labeled for inflammatory bumps. The Finacea label says efficacy for redness without papules and pustules has not been evaluated.
Can I use azelaic acid and metronidazole together?
Some dermatologists combine or alternate treatments. Ask your prescriber before layering.
Does azelaic acid burn?
Burning, stinging or itching can occur, usually during the first few weeks, according to the Finacea label.
Is OTC azelaic acid the same as Finacea?
No. Cosmetic azelaic acid products are typically lower strength and are not FDA-approved rosacea treatments.
How long do these take to work?
The Finacea label says to reassess after 12 weeks if there is no improvement.
Sources
- DailyMed: Finacea (azelaic acid) gel 15% prescribing information
- DailyMed: MetroGel (metronidazole) gel 1% prescribing information
- PubMed: Elewski et al., a comparison of 15% azelaic acid gel and 0.75% metronidazole gel in the topical treatment of papulopustular rosacea (2003)
- MedlinePlus: Azelaic acid topical
- MedlinePlus: Metronidazole topical
Medical disclaimer: This article is for educational purposes and does not replace medical advice. Consult a licensed healthcare provider before starting any supplement, medication, or treatment — particularly if you are pregnant, breastfeeding, taking other medications, or have a diagnosed medical condition.