IPL, Q-Switched Lasers, or Cryotherapy: How the Three Main Age Spot Treatments Actually Differ

Solar lentigines, the flat brown spots most people call age spots, are clusters of pigment sitting in the upper layer of the skin. They form after years of ultraviolet exposure pushes pigment-producing cells to overproduce melanin in localized patches. Because the pigment sits relatively shallow, several energy-based treatments can remove or fade them. The three most common in dermatology offices are intense pulsed light, Q-switched or picosecond lasers, and cryotherapy. They are often discussed as if they were interchangeable. They are not.

How each one works, mechanically

Intense pulsed light, usually shortened to IPL, is not a laser. It is a broadband flash of light filtered to a range of wavelengths that melanin absorbs well. The pigment in the spot heats faster than the surrounding skin, the heated pigment-containing cells are damaged, and over the following week the spot typically darkens, forms a fine crust, and flakes away. IPL treats the whole face in a single session, which is why it is popular for people with dozens of scattered spots plus background redness.

Q-switched and picosecond lasers deliver a single wavelength in extremely short pulses, measured in nanoseconds or picoseconds. The pulse is so brief that the pigment shatters through a photoacoustic effect, essentially a microscopic shock wave, before heat can spread into surrounding tissue. This makes them more precise than IPL for a discrete, well-defined spot, and generally more effective per session on stubborn lesions. The tradeoff is that treating a whole face spot by spot takes longer and the immediate whitening and crusting can look more dramatic.

Cryotherapy uses liquid nitrogen to freeze the spot. Pigment-producing cells are more sensitive to cold than the surrounding keratinocytes, so a brief, controlled freeze destroys the melanocytes in the lesion. It is fast, cheap, and requires no device beyond a canister. But the margin between destroying pigment cells and destroying too much is narrow, and the operator controls the dose by eye and by seconds of freeze time.

Where each one goes wrong

Every one of these treatments can cause the exact problem it is meant to fix: a dark mark. This happens through post-inflammatory hyperpigmentation, the skin's tendency to produce extra melanin after injury or inflammation. The risk rises sharply with darker baseline skin tones, because there is more background melanin competing for the light energy and a more reactive pigment response to injury.

IPL carries meaningful risk in darker skin because the broadband light cannot fully distinguish spot pigment from surrounding skin pigment. Many practitioners simply do not use IPL on deeper skin tones for this reason. Q-switched and picosecond lasers, particularly at the 1064 nanometer wavelength, penetrate deeper and are absorbed less by surface melanin, which makes them the more common choice for darker skin, though risk is reduced rather than eliminated.

Cryotherapy has a different failure mode: permanent hypopigmentation, a pale mark that never repigments. Because melanocytes die at warmer temperatures than the rest of the skin, an overly long freeze can leave a white spot that is arguably more noticeable than the original brown one, especially on tanned or darker skin. This risk is why many dermatologists reserve cryotherapy for lighter skin tones and isolated lesions.

The comparison in practical terms

For a fair-skinned person with many scattered spots and some redness, IPL is often the efficient choice, typically over two to four sessions. For a few well-defined, resistant spots, or for medium to darker skin, a Q-switched or picosecond laser is generally preferred, often clearing a lesion in one to three sessions. Cryotherapy remains a reasonable low-cost option for one or two spots on lighter skin when performed with a light touch, but it offers the least control of the three.

Downtime is broadly similar: expect the treated spots to darken, crust, and shed over roughly five to fourteen days. None of these treatments should blister severely or leave open wounds when dosed correctly.

The step that matters more than the device

Two points outrank the choice of technology. First, diagnosis. A flat brown spot is usually a lentigo, but early lentigo maligna, a form of melanoma, can look nearly identical. Any spot that has changed, has irregular borders or multiple colors, or looks different from its neighbors deserves evaluation, and often dermoscopy, before anyone points energy at it. Destroying an unrecognized melanoma delays diagnosis in the worst possible way.

Second, ultraviolet protection afterward. Every one of these treatments removes pigment but does nothing to the underlying sun-driven biology that created it. Without daily broad-spectrum sunscreen, spots commonly return within one to two years, and freshly treated skin repigments faster than untreated skin. The device removes the spot. Sun protection keeps it gone.

Related reading: IPL vs. Q-Switched Laser for Age Spots: What the Mechanism Actually Tells You.