IPL, or intense pulsed light, is a light-based skin treatment used to address everything from sun spots and broken blood vessels to unwanted hair and signs of aging. Unlike a laser, which fires a single wavelength of light, IPL releases broad-spectrum light across many wavelengths at once. This makes it one of the most versatile tools in dermatology and cosmetic medicine, capable of treating a wide range of skin concerns in a single device.
How IPL Works
IPL works by sending pulses of polychromatic light into the skin, where specific targets absorb the energy and convert it into heat. Those targets are natural pigments in your body: melanin (the brown pigment in hair and dark spots) and hemoglobin (the red pigment in blood vessels). When light energy hits these pigments, it heats them enough to damage the structure they sit in, whether that’s a hair follicle, a cluster of excess pigment, or a visible blood vessel, while leaving surrounding skin largely unaffected.
This principle, called selective photothermolysis, is the same concept behind laser treatments. The key difference is scope. A laser uses one precise wavelength tuned to a single target. IPL uses a range of wavelengths filtered to match the job at hand, so a practitioner can adjust the device’s settings depending on whether they’re treating redness, brown spots, or hair.
What IPL Treats
The FDA has approved IPL therapy for a long list of conditions, which broadly fall into three categories.
Pigmented lesions: sun spots (solar lentigines), freckles, melasma, and other forms of hyperpigmentation. The light targets melanin deposits, breaking them up so the body can clear them naturally.
Vascular lesions: rosacea, broken capillaries (telangiectasias), spider veins on the legs, port-wine stains, and a mottled reddish-brown discoloration of the neck called poikiloderma of Civatte. The light heats hemoglobin in abnormal blood vessels, causing them to collapse and fade.
Hair removal and skin rejuvenation: IPL damages hair follicles to slow or stop regrowth and stimulates collagen turnover to reduce fine wrinkles, improve texture, and treat acne. Because it can address pigment, redness, and texture simultaneously, IPL is popular for general “photorejuvenation,” essentially reversing accumulated sun damage across the whole face in one treatment.
IPL for Dry Eye Disease
A newer application that surprises many people: IPL is now used in eye clinics to treat a common cause of dry eyes called meibomian gland dysfunction. The meibomian glands along your eyelid margins produce an oily layer that prevents tears from evaporating too quickly. When those glands get clogged, your eyes feel gritty, irritated, and dry.
IPL appears to help in two ways. The heat from the light warms the thickened oil inside the glands, making it more fluid so it flows freely again. At the same time, the light destroys tiny inflamed blood vessels on the eyelid surface, cutting off a major source of chronic inflammation. Clinical studies show significant improvements in oil flow and reduced symptoms after a course of treatments.
What a Session Feels Like
During an IPL session, a gel is applied to the treatment area and you wear protective eyewear. The handheld device is pressed against the skin and delivers flashes of light that most people describe as a quick snap, similar to a rubber band flicking against the skin. Modern devices often include a sapphire crystal cooling tip that chills the skin’s surface on contact, reducing the heat sensation and making the experience considerably more comfortable than older IPL technology.
Sessions for facial concerns typically take 20 to 30 minutes. For hair removal, timing depends on the area being treated. Most skin concerns require a series of treatments spaced a few weeks apart. Hair removal generally takes 6 to 12 sessions to achieve full reduction, with maintenance sessions every 4 to 6 weeks afterward since hair grows in cycles and not all follicles are active at the same time.
Recovery and What to Expect
Downtime is minimal. Redness and mild swelling usually fade within 48 hours. The most common visible effect, especially when treating brown spots, is that pigmented areas temporarily darken after treatment. They can look like tiny coffee grounds on the skin for up to two weeks before flaking off and revealing clearer skin underneath. You should avoid hot water and prolonged sun exposure for at least two days after treatment, and consistent sunscreen use between sessions is essential to protect treated skin and prevent new pigment from forming.
Risks and Side Effects
IPL is generally considered safe when performed by a trained professional, but it carries real risks worth understanding. In a controlled trial of patients with light to medium skin tones, redness occurred in 87% of participants, temporary darkening of the skin in 60%, bruise-like purpura in 27%, blisters in 20%, and lighter patches of skin in 20%. These rates reflect a clinical study environment, not necessarily typical outcomes in routine practice, but they show that reactions beyond simple redness are not uncommon.
When IPL is performed by undertrained operators, the complication rate rises sharply. One study of 43 patients who experienced problems after treatments administered without physician oversight found pigment changes in over 81% and scarring in nearly 26%. Paradoxical hypertrichosis, where hair actually grows thicker or more densely in the treated area, is another recognized complication of IPL hair removal, though it’s uncommon.
Skin Tone Matters
IPL’s reliance on melanin as a target creates an important limitation. Because the light is attracted to pigment, darker skin tones absorb more energy across the skin’s surface, not just in the intended target. This raises the risk of burns, blistering, and post-treatment darkening or lightening of the skin. People with deeper complexions (typically classified as Fitzpatrick skin types IV through VI) face a meaningfully higher risk of these complications.
This doesn’t mean IPL is never used on darker skin, but it requires careful parameter adjustment and an experienced practitioner. Some providers use pre-treatment skin-lightening protocols to reduce melanin levels in the surface skin before a session, lowering the chance of unwanted pigment changes. For darker skin tones, certain laser types that use longer wavelengths may be a safer and more effective alternative.
IPL vs. Laser
The simplest way to understand the difference: a laser is a scalpel, and IPL is a Swiss army knife. Lasers emit a single, focused wavelength of light, making them extremely precise for one specific target. IPL emits many wavelengths at once across a broader area, making it more versatile but slightly less targeted.
In practice, this means IPL works well for people who have multiple concerns at once, like a combination of sun spots, redness, and uneven texture. It also tends to be faster per session because the treatment window covers a larger area of skin with each pulse. Lasers are often preferred when a single, stubborn issue needs maximum precision, such as a deep vascular birthmark or tattoo removal, which IPL cannot effectively treat. For many common cosmetic concerns, the results are comparable, and IPL sessions are often less expensive than laser treatments.