Doxycycline for Acne: How It Works, Dosage, Side Effects and More

• Doxycycline is a prescription antibiotic that is effective against acne.
• Doxycycline has antibacterial and anti-inflammatory properties.
• To increase effectiveness and safety, doxycycline is usually combined with other acne treatments.
• For optimal results, doxycycline is usually taken for three to four months.

Acne is a very common skin condition that can cause long-lasting skin damage and significant distress to those who suffer from it. 

The treatment of acne can be a challenging and lengthy undertaking, and research is ongoing into improving the effectiveness of treatment regimens for it. Doxycycline has earned a place as one of the most effective acne medications we currently have.

What Is Doxycycline?

Doxycycline is an oral antibiotic (taken by mouth) from the tetracycline group of antibiotics. Tetracyclines are broad-spectrum antibiotics; this means that they have activity against a large range of pathogens, including bacterial infections with gram-positive and gram-negative bacteria.

Doxycycline can treat a large number of infections, including pneumonia, some urinary and gastrointestinal tract infections, malaria, anthrax, Lyme disease, and Rocky Mountain spotted fever. It can also treat rosacea, a skin condition, and some sexually transmitted infections like chlamydia.

How Doxycycline Works to Treat Acne

Doxycycline has antimicrobial and anti-inflammatory effects that make it useful against acne. Acne vulgaris (more commonly just acne) is a disorder of the pilosebaceous unit (hair follicle and associated sebaceous glands) that involves bacterial, inflammatory, and hormonal components.

Doxycycline works against the main bacterial offender in acne, Cutibacterium acnes (C. acnes; formerly called Propionibacterium acnes or P. acnes). By inhibiting the multiplication of C. acnes, doxycycline can restore the natural skin microbiome balance and improve acne.

Doxycycline also exhibits direct anti-inflammatory effects. By inhibiting certain pro-inflammatory enzymes and acting as an antioxidant, it can reduce the inflammation associated with acne.

How to Use Doxycycline for Acne

Doxycycline is taken by mouth once or twice daily with food to reduce the stomach upset that can happen if taken alone.

According to the current recommendation by the American Academy of Dermatology, doxycycline should not be taken as a standalone therapy for acne. Another acne medication such as a retinoid or benzoyl peroxide should be added to the treatment regimen.

If taken for a prolonged period, there is a risk that the bacteria can develop antibiotic resistance. You should take doxycycline for three to four months then your dermatologist will re-evaluate whether you need to continue taking it. Some patients may need a longer course of doxycycline.

Dosage

The typical dose of doxycycline for acne is 50 to 100 mg twice daily or 100 mg once daily.

Concerns over the emergence of antibiotic-resistant strains of bacteria have led some experts to suggest smaller doses of 20 mg twice daily or 40 mg once daily. At this dosage range, doxycycline retains its anti-inflammatory effects and is effective against moderate inflammatory acne.

How to deal with the purging stage

When you start taking medications for acne like doxycycline, retinoids, or benzoyl peroxide, your symptoms may get worse before they begin to get better. This is called the “purging” stage and is due to increased skin cell turnover and accelerated surfacing of deep-seated comedones.

To get through the purging stage, you should adopt a gentle skin-care routine to avoid further irritation to your skin. A light moisturizer, sulfate-free cleanser, and sunscreen can help you protect your skin throughout this period.

You should not stop taking doxycycline without consulting your dermatologist. The purging stage typically lasts between four and six weeks; if it lasts more or if the symptoms are too bothersome, check in with your dermatologist.

Things that can make your acne worse include:

• Excess unprotected sun exposure
• Diets high in sugars, saturated fats, and dairy products
• Heavy makeup

Results

Doxycycline is an effective treatment for acne vulgaris and is a component of the first-line treatment regimen for moderate and severe inflammatory acne.

A published review of multiple clinical trials found that doxycycline produced up to a 75% reduction in inflammatory acne lesions and up to a 54% reduction in comedones (blackheads and whiteheads) in the included trials.

Doxycycline does not treat pre-existing acne scars as they are no longer actively inflamed.

How long does it take to work?

The optimal combination therapy of doxycycline, benzoyl peroxide, and a topical retinoid can produce improvements in as little as two weeks. However, it can take some people up to 12 weeks to see improvements.

Interactions and Side Effects

Some drugs can decrease the absorption of doxycycline into your bloodstream or make it less effective such as:

• Antacids
• Iron pills and iron-containing multivitamins
• Some seizure medications such as barbiturates, carbamazepine, and phenytoin
• Calcium and magnesium salts
• Some antibiotics such as rifampin

Special care and monitoring should be exercised when combining doxycycline with the following drugs:

• Aminolevulinic Acid (ALA): can cause an increased risk of skin reactions.
• The blood-thinner warfarin: doxycycline can increase the risk of bleeding with warfarin.
• Some retinoids such as isotretinoin: combination with doxycycline increases the risk of causing elevated pressure in the brain. Some retinoids such as Adapalene and Bexarotene are safe with doxycycline and are part of the combination treatment regimen for acne.

This is not a comprehensive risk of interactions; you should consult your physician before making any changes to your medications.

Doxycycline can cause several side effects that include:

• Loss of appetite, diarrhea, nausea, or vomiting
• Rash
• Photosensitivity or increased susceptibility to sunburns.
• Esophagitis or inflammation of the esophagus which can manifest as heartburn or chest discomfort. To help prevent this, take doxycycline with a full glass of water and avoid lying down for 30 minutes after taking it.

More serious adverse effects are rare and include:

• Permanent damage to teeth and bones in children and infants whose mothers took doxycycline during pregnancy. Pregnant women and children under the age of eight should not take doxycycline. 
• Severe skin reactions called Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis.

Alternatives

Antibiotic therapy is now a cornerstone in the management of acne. Other antibiotics that have shown effectiveness in fighting acne include macrolides, trimethoprim, and other members of the tetracycline family.

Tetracyclines

Doxycycline, minocycline, and tetracycline (named after the group) are all effective acne treatments. Doxycycline and minocycline have replaced the older tetracycline as the drugs of choice in severe and moderate acne.

Doxycycline and minocycline are comparable in effectiveness; however, doxycycline is less likely to cause side effects such as gastrointestinal upset.

Macrolides

Macrolide antibiotics such as erythromycin and azithromycin are effective acne treatments. Macrolides are prescribed as alternatives in people who cannot take doxycycline.

Trimethoprim

While Trimethoprim-Sulfamethoxazole (TMP-SMX) is an effective antibiotic for acne, the potential for severe side effects such as suppression of bone marrow function and toxic epidermal necrolysis (TEN) limit its use.

TMP-SMX is recommended as a third-line antibiotic for acne resistant to treatment or in people who cannot take tetracycline antibiotics.

Takeaway

Doxycycline is an antibiotic with anti-inflammatory properties that is prescribed as a first-line treatment for acne. It is effective in treating moderate to severe inflammatory acne. Doxycycline is usually taken once or twice daily for three to four months and it can take several weeks to see improvements.