Which Laser is Best for Fine Dark Hairs? I've Used the Soprano IPL and It Didn't Work at All.

The best machine for laser hair removal ultimately depends on the individual.  The machine, in general should be a high power machine.  There are a lot of machines out there and many of them are weak, which will not provide a great result.  The machines made by Candela, Lumenis, and Palomar are examples of high power machines.  Dark hair is usually the easiest to remove and if the patient has light skin, a high power machine should work great.  If the skin is dark, the power will have to be turned down some, or an Nd:YAG machine can be used.  In general, the Nd:YAG is not as effective as the other machines, but you can still get an improvement.  Be sure to visit a facility with an experienced physician to better understand your options.

A wide variety of medical lasers and light systems are used to remove unwanted hair, however most lasers are not effective for all skin types and hair colors. The Elos laser hair removal system is designed for permanent hair reduction by combining both optical and radiofrequency energy to deliver satisfying, longer lasting results with less discomfort than previous laser systems. All skin and all hair colors including gray and blonde hair are effectively treated. Faces, backs, arms, legs, faces, and bikini lines can be treated including those individuals with darkly pigmented skin. Treatments are administered every 4 weeks and generally 3 to 5 treatments are sufficient.

The right answer depends on your skin color and the way your skin responds to the sun. In general, fair skinned individuals do best with the Alexandrite  or the diode lasers and the Nd:YAG laser is safer for darker complected people. The hairs most sensitive to laser light are in the early growing phase of the hair cycle so expect multiple treatments.  IPL can be used for laser hair reduction but the last time I researched this, lasers were still the gold standard! I prefer lasers that incorparate cooling into the handpiece which reduces the risk and the discomfort associated with the procedure.  

If you have light skin and dark hair, the best laser would be the Alexandrite.  If you have darker skin and dark hair, the best laser would be the Yag.  Expect to need several treatments with any laser though.