Peridex Side Effects: What to Expect and When to Call Your Doctor

Peridex (chlorhexidine gluconate 0.12% oral rinse) is generally well-tolerated, but it does come with several predictable side effects that patients should know about before they start using it. Most are manageable and reversible; a few rare reactions require prompt medical attention. Here is what to expect.

The Most Common Side Effects of Peridex

The three most common side effects associated with chlorhexidine gluconate oral rinse are:

1. Tooth and Surface Staining

Staining is the most frequently reported side effect of Peridex. You may notice brown or yellowish discoloration on your teeth, tongue, and the inside of your cheeks as early as one week after starting treatment. This happens because chlorhexidine binds to tooth surfaces and reacts with certain foods and beverages (especially coffee, tea, and red wine) to produce a visible stain.

The staining does not damage your teeth or affect their structure. Most surface staining can be removed by your dentist at your next professional cleaning. However, staining on dental fillings with rough surfaces or on exposed root surfaces may be more difficult to remove. To minimize staining: avoid coffee, tea, and red wine for at least 30 minutes after using the rinse, and attend your 6-month dental cleanings as scheduled.

2. Increased Tartar (Calculus) Buildup

Clinical studies have found that Peridex users experience increased supragingival (above the gumline) calculus formation compared to non-users. This is why the FDA labeling recommends dental cleanings at intervals not exceeding six months while using the rinse. Your dentist will remove calculus deposits at your regular appointments.

3. Changes in Taste

Many patients notice a bitter aftertaste after using Peridex, and some experience altered taste perception for up to 4 hours after rinsing. This effect often becomes less noticeable as you continue using the medication. Taste usually returns to normal after stopping treatment. In rare post-marketing reports, a small number of patients have experienced permanent taste alteration—this is uncommon.

Other Reported Side Effects (Less Common)

Oral mucosal irritation, minor irritation, or superficial peeling of oral tissues

Dry mouth sensation

Mouth sores or ulcers (rare; each occurs in less than 1% of patients in clinical trials)

Parotid gland swelling or salivary gland inflammation (sialadenitis) — rare, post-marketing reports only

Serious Side Effects: When to Seek Immediate Help

Serious allergic reactions to chlorhexidine gluconate are rare but can be life-threatening. Stop using Peridex and seek emergency medical attention immediately if you experience:

Hives or severe skin rash

Wheezing or difficulty breathing

Swelling of the face, lips, tongue, or throat

Cold sweats, dizziness, or fainting

Rapid or irregular heartbeat

These are signs of anaphylaxis, a life-threatening allergic reaction. Call 911 or go to your nearest emergency room immediately.

What to Do About Staining

Many patients are concerned about tooth staining. Here is how to minimize it:

Use the rinse after meals, not before—especially avoid staining beverages (coffee, tea, red wine) for at least 30 minutes after rinsing

Brush and floss daily to reduce plaque, which worsens staining

Attend your 6-month dental cleanings—professional polishing removes most chlorhexidine staining

Ask your dentist about tooth whitening after your course of treatment is complete

Side Effects in Children

Peridex is not approved for use in children under 18. In small children, accidental ingestion can cause nausea, slurred speech, and slow movement. Keep Peridex out of reach of children. If a child accidentally swallows Peridex, call Poison Control at 1-800-222-1222 immediately.

For information on what medications and foods to avoid while taking Peridex, see our guide on Peridex drug interactions. And if you're having trouble filling your Peridex prescription, medfinder can locate it in stock near you.