Not everyone agrees, but more and more it seems people say that LED and laser are identical in terms of the biological effect assuming apples-to-apples specifications (same wavelength and same mW / cm2 power output).
One example is this web page, go about halfway down to the section called "Laser Light Versus LEDs".
http://heelspurs.com/led.html
"There has been a lot of interest and money in low level laser therapy (LLLT) for healing, but there is no reason to believe that the coherent light from a laser is any better than LEDs, sunlight, or halogen lights. (Unfortunately, authors of the last 10 years or so have twisted the historical meaning of LLLT to mean "low level LIGHT therapy" since lasers are fading away in importance in this area.) Laser light might be more efficient since it may get through the skin more easily, but it does not penetrate more deeply once the light is beneath the skin, and cells do not know the difference: all photons are the same and the benefits are based on the action of each individual photon, not on bulk properties such as all the photons having the same polarity or coherency. The word "laser" has a superior marketing appeal for companies because it sounds interesting and mysterious. It also costs a lot which means patients can't do it on their own."