Although it is often called laser hair removal, IPL (stands for intense pulsed light) is not technically a laser. The main difference in a Laser and IPL is that lasers are of a single wavelength (which also means a single color or is monochromatic). The light rays are all targeted in the same direction with lasers.
With IPL, the light used is mostly in the visible spectrum of 400-1200 nm wavelength and hence the flashes of light appear white to orange in hue.
What’s common with both is that they depend on the same principle of ‘selective photo-thermolysis’. In simple language, this means that the light energy is absorbed by the hair follicles as heat.
The heat destroys the hair follicles and therefore, the hair does not grow back. The word selective is added because the energy is not absorbed by surrounding structures, which is why there is no blistering of the surrounding skin due to heat. Both laser ad IPL use melanin as the target chromophore1
Is IPL better than lasers?
Not really. There are some factors that decide whether an individual could get better results from IPL or laser hair removal. One of the basic things in this is that lasers have far more precise action and so the settings required for them are also more precise. They can hence only be used in a clinical setup.
Most of the at-home devices use IPL given the fact that you have much lesser chances of hurting yourself. That being said, the energy used in home devices is usually too low for safety reasons and you are unlikely to get long term results. Clinical IPL devices are far more effective.
Till a few years back, IPL was considered inferior to laser hair removal in terms of long terms results. However, with newer technologies, IPL gives results equal to laser hair removal1
When does IPL give better results? When the concentration of melanin is higher, therefore in thick, dark, coarse hair1, coupled with a fair skin tone.
When does Laser hair removal provide better results? In darker skin tones where the photochromatic targeting needs to be more precise for the hair follicle rather than in epidermal skin.2
Apart from this, IPL covers a larger area with a single burst of light, so the treatment times required per session are lower. The number of sessions required however may be higher.
How does IPL work exactly?
As shared already, it works with the generation of scattered pulses of light at high energy. In modern devices, the light bursts are usually achieved by passing electricity through a xenon filled gas chamber. This energy is then released to the skin with the help of a sapphire or quartz block.
Cooling systems are used to protect the epidermis. The energy levels and wavelengths (filtered) are chosen such that they only target the melanin present in hair follicles to promote their necrosis.