Nd:YAG laser using a carbon-based lotion was considered to be a long-term and even permanent for years, until published clinical data showed that this was incorrect.

Q-Switched with Carbon-Based Lotion

Early published medical data showed that using Nd:YAG with the carbon lotion lead to 27% to 66% reduction at 3 months after one treatment. One 15-subject research found long pulse Nd:YAG more efficient and less painful when compared to alexandrite treatment One large study of patient contentment at six months after multiple procedures showed those seeking to thin hair were generally satisfied, but 75% of those expecting more were not pleased.  One research observed full regrowth by month six. Another investigation observed that side effects were less likely with this treatment compared to other lasers. Side effects are less after treatment with Nd:YAG with the carbon lotion than with ruby or alexandrite devices.

One study showed that treatment is probably more efficient on anagen hairs. Histological evidence suggests thermal injury occurs to about 1 mm deep. One small study reported that it is possible to treat “shaving bumps” (pseudofolliculitis barbae) and another research suggests a successful treatment of infants born with excessive amounts of downy hair (hypertrichosis lanuginosa congenita)

Long Pulse Nd:YAG

The one published study showed that 15 subjects had 59% reduction at 3 months. An unpublished report noticed skin discoloration in tanned skin is rare and decided by 6 months. Eleven patients followed had about 30% reduction at 6 months. Another unpublished manufacturer study with a long-term follow up showed that 25 subjects had median of 27% reduction at 3 months after a single treatment.

Also in this report, observers of before and after photos thought the after photos looked better in three-fourths of the treated areas, with the control looking better in half the treated areas. Areas which had one or two procedures were observed to have 39% and 50% reduction at 12 months, respectively.