IPL, Light Absorption, and MaxG (Palomar) — Explained by Day One Clinic Gangnam

Even people who have never visited a dermatology clinic have heard of IPL — it is one of the most widely known procedures in the field.

While long-pulse devices have become increasingly popular and IPL use has declined somewhat, IPL remains one of the treatments capable of delivering the most visible results when used correctly.

The performance gap between domestic Korean IPL devices and original imported IPL devices — such as the Palomar MaxG or the Lumenis One — is quite pronounced. Clinics without original imported devices relied heavily on domestic IPL for a time but have been shifting toward long-pulse lasers recently, whereas clinics equipped with original imported IPL systems continue to rely on them because of their superior results.

(The domestic-versus-imported performance gap may be widest for IPL compared with any other device category. Domestic HIFU, hair-removal, and Nd:YAG systems can perform reasonably well, but the gap in IPL results — especially for faint pigmentation — seems notably large.)

In any case, let's take a closer look at the well-known name that is IPL.

IPL stands for Intense Pulsed Light. Strictly speaking, it is not a laser.

Clinics often refer to many devices as "lasers" for simplicity, but IPL technically does not qualify as one.

A laser uses a specific medium to produce light of a specific wavelength, whereas IPL uses no such medium. Instead, it emits a broad spectrum of wavelengths from a xenon flash lamp and delivers them in strong pulses.

As explained previously, pigmentation is treated using the principle of Selective Photothermolysis. The graph above shows the absorbance curves of each chromophore — each chromophore has wavelengths it preferentially absorbs. By delivering light at a wavelength well absorbed by the target chromophore, the energy is converted to heat, destroying the target tissue at high temperature.

A standard IPL flash lamp emits light across the 400–1,200 nm range. In practice, cut-off filters are applied to limit output to an appropriate wavelength band. Most systems use a 560 nm or 590 nm cut-off filter, eliminating shorter wavelengths and passing light in the 560–1,200 nm or 590–1,200 nm range.

The Palomar MaxG uses two cut-off filters simultaneously, allowing a narrower and more precisely defined wavelength range. Light is emitted in only two bands — 500–670 nm and 870–1,200 nm — which results in significantly fewer side effects and better outcomes compared with conventional IPL devices.

In the absorbance graph, the blue curve represents melanin and the red curve represents hemoglobin (Hb). The green-shaded area (labelled LuxG) indicates the two filtered wavelength bands used by the MaxG.

The 500–670 nm band targets Hb and melanin, while the 870–1,200 nm band targets Hb and MetHb, making the MaxG effective for both pigmentation and vascular treatment.

Our clinic has both a domestic IPL device and the original Palomar MaxG, and the difference in results between the two is substantial. The MaxG's key advantages over domestic or standard IPL include a markedly lower incidence of post-inflammatory hyperpigmentation (PIH), and — more importantly — a noticeably better response to faint or light-colored pigmentation.

(This is what we consider the most significant difference between domestic and original imported IPL, and the reason we recommend seeking treatment on an original device. Faint pigmentation simply does not respond well to a lower-quality machine no matter how many sessions are done. Higher-quality devices tend to respond better to faint pigmentation.)

We will discuss the MaxG in more detail in a later post.

Returning to IPL in general:

Q. Who benefits most from IPL?

A. IPL is most effective for epidermal pigmented lesions such as age spots and freckles. Results are often excellent within just two or three sessions, making it one of the procedures with the highest patient satisfaction.

As the absorbance graph shows, IPL's broad-spectrum light can address multiple chromophores simultaneously. Because the device also emits wavelengths that are well absorbed by hemoglobin, vascular lesions can be treated at the same time as pigmentation.

Clinical experience also confirms a skin rejuvenation effect: repeated treatments can produce a noticeable improvement in skin radiance. This is thought to occur because IPL energy reaching the dermis breaks down existing collagen; the resulting wound-healing response activates fibroblasts, which synthesize new collagen. For photorejuvenation, approximately four to five sessions are recommended, with results beginning to appear gradually two to three weeks after each treatment.

Q. What side effects can IPL cause?

A. Patients with darker skin, those who have been recently tanned by sun exposure, or those who tan very easily have a higher concentration of chromophores such as melanin in the skin. Treating such patients at standard energy settings can produce an excessive reaction. Scabbing may occur in the shape of the IPL tip, and this can leave post-inflammatory hyperpigmentation (PIH).

One of the most commonly seen photos illustrating IPL side effects is the image on the left.

This type of reaction can occasionally occur if more energy than expected is delivered. The photo is included as a reference only — most people undergoing IPL will not experience this, so there is no need to be alarmed.

Another advantage of the MaxG is that its handpiece tip is smaller than the large rectangular tip of a conventional IPL device, so even if an excessive reaction does occur, any resulting marks will not be as large in area.

If you have found this post by searching for IPL side effects, or if you are concerned about pigmentation that developed after an IPL treatment, you generally do not need to worry excessively.

The photos may look alarming, but post-inflammatory pigmentation does gradually fade with time and eventually resolves.

Combining laser toning treatments with oral tranexamic acid (doransamin) can speed up the fading process, so this is a manageable issue.

Q. What aftercare is needed following IPL?

A. If your face feels hot on the day of treatment, apply a cold wet towel to cool the skin. Removing heat from the face as quickly and thoroughly as possible helps reduce the risk of side effects.

If there is little or no sensation of heat, cooling is not necessary, but thorough application of sunscreen is essential.

Without adequate sun protection, pigmentation may darken further, so it is important to be diligent about sunscreen use.

The scabbing that can form after IPL is not a thick, raised crust like a wound scab. It appears as a subtle darkening of the existing pigmentation. You should not rub or forcibly remove it — it will fall off on its own within about a week, leaving the skin visibly brighter.

Sessions are typically spaced two weeks apart. If results seem minimal or no scabbing formed at all, the energy can be adjusted and an earlier session may be done without significant concern.

For vascular treatment specifically, it is important to maintain the two-week interval and not to exceed it, as capillaries regrow quickly.

In summary:

1. The performance difference between domestic and imported IPL devices is significant.

2. Patients with darker skin or those who tan quickly and deeply in the sun require much lower IPL energy settings.

3. IPL is highly effective for patients with numerous freckles or age spots. It is not generally indicated for melasma.

Left: before treatment. Right: after treatment.

Looking at the before photo, the pigmentation may feel dark to the patient, but light brown spots of this type do not respond well to standard IPL.

After MaxG treatment, both the pigmentation itself and the overall skin tone are noticeably improved compared to before.

A rejuvenation effect is also visible, with improvement in skin texture as well.

This patient is another example.

As seen in the before photo on the left, brown pigmentation of this type is difficult to treat with standard IPL.

Using MaxG combined with laser toning, clear improvements in pigmentation, skin texture, and pore appearance are achieved.

Facial redness (rosacea-type flushing) requires multiple repeat sessions and is not easy to treat even with dedicated vascular lasers.

However, IPL and MaxG can provide a meaningful degree of improvement for facial redness.

In the case shown above, a noticeable reduction in visible vessels and redness can be seen. Continued repeat sessions would be expected to yield further improvement.