Laser, IPL, or Cryotherapy for Age Spots: What Actually Happens Under the Skin

Age spots, known clinically as solar lentigines, are flat, tan to dark brown patches that develop after years of ultraviolet exposure. They are not simply excess pigment sitting on the surface. A lentigo involves an increased number of melanocytes along the basal layer of the epidermis, plus elongated rete ridges and melanin distributed through surrounding keratinocytes. That anatomy matters, because every effective treatment has to reach that pigment without damaging the tissue around it. The three workhorses in most dermatology offices are pigment-targeting lasers, intense pulsed light, and cryotherapy. They are often discussed as interchangeable. Mechanistically, they are not.

How pigment lasers work. Q-switched and picosecond lasers rely on a principle called selective photothermolysis. The laser emits a specific wavelength, commonly 532, 694, 755, or 1064 nanometers, that melanin absorbs far more strongly than the surrounding water-rich tissue. The pulse is extremely short, measured in nanoseconds or picoseconds, which is shorter than the time it takes heat to spread out of the pigment-containing cells. The result is a rapid photoacoustic and photothermal effect that shatters melanin granules and injures pigment-laden cells while sparing most of the neighboring skin. The fragmented pigment is then cleared by the immune system or shed as the spot darkens, crusts lightly, and flakes off over roughly 7 to 14 days. Because targeting is wavelength-based rather than mechanical, lasers tend to offer the most precise pigment destruction of the three options, and studies comparing modalities for lentigines generally report the highest clearance rates with the fewest treatments, often one to three sessions.

How intense pulsed light works. IPL is not a laser. It is a filtered flashlamp that emits a broad band of wavelengths, typically somewhere between 500 and 1200 nanometers depending on the cutoff filter chosen. Melanin still absorbs much of that light, so the mechanism is related, but the energy is delivered over milliseconds rather than nanoseconds. That longer pulse produces gentler heating rather than a photoacoustic shattering effect. Practically, this means IPL usually requires more sessions, commonly three to five, and produces subtler per-session change. The tradeoff is a larger treatment head and the ability to cover a whole cheek, chest, or hand quickly, which suits people with widespread mottled pigment rather than a handful of discrete spots. The characteristic response is that treated lentigines darken and take on a coffee-ground appearance for several days before sloughing.

How cryotherapy works. Liquid nitrogen destroys pigment through cold rather than light. Melanocytes are notably more sensitive to freezing than keratinocytes, dying at temperatures around minus 4 to minus 7 degrees Celsius, while general skin cells tolerate colder temperatures. A brief, controlled freeze can therefore preferentially eliminate the pigment-producing cells in a lentigo. Cryotherapy is fast, inexpensive, and requires no device beyond a spray canister or applicator. Its weakness is precision. Freeze depth and margin are judged by eye, and because melanocytes are so cold-sensitive, overtreatment readily produces a permanent white spot, called hypopigmentation, that can be more noticeable than the original lentigo. This risk rises significantly in medium and darker skin tones.

Choosing between them. Skin tone is the single biggest variable. In lighter phototypes, all three modalities perform reasonably well, and the decision often comes down to how many spots exist and how much downtime is acceptable. In darker phototypes, melanin in normal surrounding skin competes for laser and IPL energy, raising the risk of burns and post-inflammatory hyperpigmentation, and cryotherapy carries a meaningful hypopigmentation risk. For these patients, longer wavelengths such as 1064 nanometers, conservative settings, test spots, and sometimes topical regimens instead of devices are the safer route. Cost and access also differ: cryotherapy is widely available and cheap per lesion, while picosecond lasers sit at the top of the price range.

Two caveats that apply to every option. First, no treatment should proceed on a pigmented lesion that has not been evaluated. Lentigo maligna, an early form of melanoma, can closely mimic a benign age spot, and destroying it with a laser or freeze removes the ability to diagnose it. Any spot with irregular borders, multiple colors, recent change, or a history of bleeding warrants dermoscopic examination first. Second, recurrence is the norm without sun protection. Treatment removes existing pigment and pigment cells, but it does not change the UV-damaged field that produced the spot. Daily broad-spectrum sunscreen is not an optional aftercare suggestion, it is the mechanism by which results last.

The short version: lasers offer precision and speed of clearance, IPL offers coverage for diffuse mottling, and cryotherapy offers accessibility at the cost of control. None of them is universally best. The right match depends on skin tone, spot pattern, budget, and a proper diagnosis before anything touches the skin.

Related reading: Laser, IPL, or Cryotherapy for Age Spots: How the Three Main In-Office Options Actually Differ.