IPL, or intense pulsed light, is a non-laser light therapy used to treat sun damage, redness, broken blood vessels, dark spots, and unwanted hair. It works by sending broad-spectrum light into the skin, where it’s absorbed by specific targets like pigment or blood vessels, heating and breaking them down so the body can clear them naturally. It’s one of the most common cosmetic procedures performed in dermatology offices and medical spas, prized for its versatility and relatively quick recovery.
How IPL Works
IPL devices use a high-output flashlamp to produce a broad range of light wavelengths, typically between 500 and 1,200 nanometers. This is fundamentally different from a laser, which emits a single, precise wavelength. The broad spectrum is actually the point: it allows IPL to target multiple skin concerns in the same session.
The underlying principle is called selective photothermolysis. In plain terms, different structures in your skin absorb different wavelengths of light. Melanin (the pigment in dark spots, freckles, and hair follicles) absorbs certain wavelengths. Hemoglobin (the protein that makes blood red) absorbs others. When these targets soak up the light energy, it converts to heat, which damages or destroys the unwanted cells while leaving surrounding tissue intact.
Practitioners customize the treatment by using cutoff filters that block shorter wavelengths and let longer ones through. Filters ranging from 515nm to 755nm allow the device to be tuned for different problems. A shorter cutoff targets superficial pigment. A longer one reaches deeper structures like blood vessels or hair follicles. This flexibility is what makes IPL useful across such a wide range of skin conditions.
What IPL Treats
IPL is most commonly used for signs of sun damage and aging, often grouped under the term “photorejuvenation.” The specific conditions it addresses include:
- Sun spots and age spots (solar lentigines), the flat brown patches that accumulate on the face, chest, and hands
- Rosacea and facial redness, where visible blood vessels and persistent flushing respond well to light targeting hemoglobin
- Broken capillaries (telangiectasia), the fine red or purple lines that appear on the nose and cheeks
- Freckles and uneven skin tone, where scattered melanin pigment is broken up over multiple sessions
- Hair removal, where melanin in the hair follicle absorbs enough heat to damage the follicle and slow regrowth
For hair removal specifically, IPL works best when there’s a strong contrast between hair color and skin color. Dark hair on lighter skin gives the device a clear target. Light blonde, gray, or red hair contains less melanin, making it harder for the light to do its job.
IPL vs. Laser Treatments
The main distinction is precision versus coverage. A laser emits a single wavelength of coherent, focused light. This makes it more accurate for targeting a specific problem at a specific depth. IPL emits multiple wavelengths simultaneously, covering a broader area with each pulse but with less pinpoint control.
In practical terms, IPL is often better suited for treating diffuse concerns spread across a large area, like overall sun damage on the face or chest. Lasers tend to be the better choice for isolated, stubborn lesions or deeper skin concerns like acne scars. Many dermatologists use both, choosing the tool that fits the problem. IPL sessions also tend to cost less per treatment than laser procedures, which factors into the decision for conditions that need multiple visits.
What a Session Feels Like
A typical IPL session takes 20 to 30 minutes for a full face. Your provider will clean the treatment area, apply a thin layer of cooling gel (though some newer devices use built-in sapphire cooling plates instead), and give you protective eye shields. The handpiece is pressed against the skin and delivers pulses of light. Most people describe the sensation as a quick snap, like a rubber band flicking against the skin. It’s uncomfortable but tolerable, and modern devices with active cooling systems have made it noticeably more comfortable than older technology.
Immediately afterward, the treated area feels like a mild sunburn, a sensation that usually fades within 24 hours. The more interesting part comes in the days following. Dark spots and freckles will temporarily darken, sometimes taking on a “coffee ground” appearance as the pigment rises to the surface. This looks worse before it looks better. Over the next one to two weeks, those darkened spots flake off as the skin sheds, revealing clearer skin underneath. Most physical side effects like redness and mild swelling resolve within 48 hours.
How Many Sessions You’ll Need
Most dermatologists recommend starting with a series of 3 to 6 sessions, spaced about 4 weeks apart. The number depends on the severity of the condition being treated. Mild sun damage might clear with 3 sessions. More extensive discoloration or rosacea could take 5 or 6. Hair removal typically falls on the higher end, since hair grows in cycles and only follicles in the active growth phase respond to treatment.
Results aren’t permanent in the way a surgical procedure might be. Sun exposure, hormonal changes, and natural aging continue to affect your skin. Most patients benefit from maintenance treatments every 6 to 12 months to sustain their results, with the interval depending on lifestyle factors like how much time you spend in the sun.
Risks and Side Effects
The most common side effects are mild: temporary redness, slight swelling, and the darkening of pigmented spots that resolves as the skin sheds. These are expected parts of the process, not complications.
More serious complications do occur, particularly when treatment settings are too aggressive or the device isn’t appropriate for the patient’s skin. A retrospective study of 50 patients who experienced complications found that pigmentation changes occurred in 81% of cases, scarring in about 26%, and textural changes in 14%. The most frequent treatment errors behind those complications were excessive energy application (63% of cases) and using the wrong device for the indication (40%). These numbers reflect a study specifically examining problem cases, not overall treatment outcomes, but they highlight how much the skill and judgment of the provider matter.
Blistering and crusting can happen if the skin absorbs too much energy. This risk increases with higher energy settings, thinner skin, and darker skin tones. Folliculitis, a temporary inflammation of hair follicles, is another possibility in areas treated for hair removal.
Skin Tone and Safety
This is the most important safety consideration with IPL. Because the device targets melanin, it can’t easily distinguish between unwanted pigment (a sun spot or hair follicle) and the melanin naturally present in darker skin. People with deeper skin tones face a higher risk of burns, hyperpigmentation (dark patches), and hypopigmentation (light patches) after treatment.
IPL is particularly challenging for individuals with darker complexions, classified as Fitzpatrick skin types III through VI on the standard dermatology scale. That range includes medium olive skin through very dark brown skin. Another unusual risk in this group is paradoxical hypertrichosis, where IPL hair removal actually stimulates new hair growth in the treated area instead of reducing it.
This doesn’t mean darker-skinned patients can never use IPL, but it does mean the treatment requires an experienced provider who understands how to adjust settings appropriately. Some patients in this range are better served by certain laser technologies that can bypass surface melanin more effectively. If you have a medium to dark skin tone, this is worth discussing specifically before committing to treatment.
Choosing a Provider
IPL devices are widely available, and regulations on who can operate them vary significantly by state. The complication data underscores that most serious side effects trace back to operator error: too much energy, wrong filter, or failure to account for skin tone. A board-certified dermatologist or a licensed aesthetician working under physician supervision is your safest bet. Ask about their experience with your specific skin type and the condition you’re treating. A provider who does a test patch on a small area before your first full session is being appropriately cautious, and that’s a good sign.