The Good:

À   HENNA is a natural product resulting in a brown stain of the skin.

À    Ask the HENNA artist what is in their mix. There are only 4 ingredients: HENNA, lemon, a sugar and essential oils.

À    HENNA is applied wet (like frosting) and dries (like tooth paste).

À    The longer the paste is on the skin (4+ hrs), the darker the stain can become.

À    Stains can last 2+ weeks if care is taken. *No water on stain; protect with cocoa butter or olive oil.

À    HENNA has a 5000 year record of safety. Only those with G6PD deficiency should avoid henna. Those allergic to citrus or spa treatments should let the artist know to ensure they will not have a sensitivity reaction to the mix.

The Bad:     

À  Black henna stains black and is NOT henna!

À    Black henna often contains PPD, a toxic chemical that can severely blister the skin and cause liver and kidney damage. Even one application can result in a lifetime of health problems. (see pictures below)

À   Kits often contain unidentified oils that are harmful. ‘Mehndi’ oil can contain kerosene. This enters the blood stream.

À    Premade cones are often wrapped in a lead foil so they hold up well. The lead leeches into the henna and is transferred to the skin in use.

And the ugly:

Before Black Henna application:   Reaction to Black Henna:     Bride’s Black Henna scars:

(Trouble loading pics - will be up soon)      
bottom line:

Always ask what is in the henna mix (henna, lemon, sugar, essential oil), the color of the resulting stain (brown), and if the design withstands water (no). As a certified HENNA artist, your safety is my top concern. Please be safe.

Want to read more? Below are several links to news articles about black henna as well as links to some interesting articles about wonderful, natural, safe brown henna.

http://www.hennapage.com/henna/ppd/whatisppd.html
http://www.hennapage.com/henna/encyclopedia/medical/g6pd.html
http://www.hennapage.com/henna/encyclopedia/medical/g6pd.html
http://xelodasideeffects.blogspot.com/

Henna related News Articles: 
Henna blog for cancer patients
Henna used to catch a thief?
Hospital blog about henna and Chemo treatment
Blog for people looking for help with the effects of the medication Xeloda
Medical information regarding Radiotherapy and Henna
Henna to catch a theif? 
Health and Henna
Henna as a cancer treatment?
Black henna/PPD articles:
News/video about black henna/PPD
Information about Black henna/PPD
Baylor University Black henna warning
Black henna warning with pictures
Black henna burns instead of wedding joys
This has a close up picture of the brides hands. 
Florida Department of Health puts forth a Black Henna warning
Another story. Can you read Cancun under the butterfly? 
ABC warning against Black Henna allergic burns
N. American artists and Black Henna