Jagua vs Henna vs "Black Henna": Color, Chemistry and Safety

Walk through a summer festival or a beach boardwalk and you will see temporary body art sold under all sorts of names: henna, mehndi, jagua, black henna, blue henna. Some of these are traditional plant stains with long histories. One of them, "black henna," is often something else entirely and can cause serious skin injuries. This guide explains how the three compare so you know what you are getting.

Quick comparison

	Jagua	Natural henna	"Black henna"
Source	Fruit of Genipa americana	Leaves of Lawsonia inermis	Often henna or other base mixed with PPD hair dye, or hair dye alone
Coloring compound	Genipin	Lawsone	Para-phenylenediamine (PPD) and similar dyes
Final color	Blue-black	Orange to reddish-brown	Jet black, very quickly
Time to full color	About 24 to 48 hours	About 24 to 48 hours	Often within an hour or so
Typical longevity	About 1 to 2 weeks	About 1 to 3 weeks	Varies
Main safety concern	Uncommon allergic reactions	Uncommon allergies; adulterated products	Severe reactions and lasting sensitization

Jagua: blue-black from a fruit

Jagua comes from the unripe fruit of Genipa americana, a tree native to tropical Central and South America, where Indigenous peoples of the Amazon have used it for body decoration for generations. The fresh juice is almost colorless. Its active compound, genipin, reacts with proteins in the outer layer of skin and slowly forms a dark blue pigment over roughly a day or two.

The result is a blue-black stain that resembles a fresh ink tattoo. It lasts about one to two weeks before fading as the skin exfoliates. For a deeper introduction, read what jagua is and how it works.

Natural henna: the reddish-brown classic

Henna is made from the dried, powdered leaves of the henna plant, Lawsonia inermis. Mixed into a paste, it has been used for centuries across South Asia, the Middle East and North Africa, especially for weddings and festivals. Its coloring molecule, lawsone, binds to keratin in the skin.

Fresh henna stains start out pale orange after the paste is removed and deepen over a day or two into shades ranging from orange to rich reddish-brown or a deep mahogany. Palms and the soles of the feet usually show the darkest color. What natural henna never produces is true black. If someone offers you "henna" that turns jet black within an hour, it is not plain henna.

A useful rule of thumb: plant henna is warm brown, jagua is cool blue-black, and anything that turns pitch black almost instantly deserves suspicion.

"Black henna": the one to avoid

"Black henna" is a marketing name, not a plant. These products frequently get their color from para-phenylenediamine (PPD), a dye used in permanent hair coloring. Sometimes it is mixed into henna, and sometimes the artist simply uses hair dye on the skin.

PPD can cause allergic contact dermatitis. Reactions may include itching, redness, blistering, weeping sores and raised welts that follow the shape of the design, sometimes appearing days after application. Some people are left with lasting skin discoloration or scarring. Just as importantly, a reaction can sensitize you for life, meaning you may react to hair dyes, some clothing dyes and related chemicals in the future.

The US Food and Drug Administration explains in its fact sheet on temporary tattoos, henna and "black henna" that PPD is not permitted in cosmetics intended for the skin and that it has received reports of injuries from products marketed as black henna.

Never get a "black henna" tattoo, especially on a child. If you have had a reaction to black henna in the past, talk to a doctor before using hair dye or trying any new body art product, including jagua.

The chemistry, side by side

All three products leave color in the outer layer of the skin rather than injecting it deeper, which is why they are temporary. The difference is in what does the staining:

Genipin (jagua) reacts with amino acids in skin proteins to form a blue pigment. The reaction takes time, so the color builds gradually.
Lawsone (henna) binds to keratin and oxidizes over a day or two, darkening from orange to brown.
PPD (black henna) oxidizes rapidly to a dark color. It is a strong sensitizer, which is the root of its safety problem.

How long each one lasts

Because every option stains the outermost, constantly shedding layer of skin, they all fade with time. Jagua usually lasts around one to two weeks. Henna on hands and feet can last up to two or three weeks, but fades faster on thinner skin such as the upper arm or back. Placement, skin type, washing habits and swimming in chlorinated water all play a part. Our guide to how long jagua lasts breaks down these factors.

A note on US regulation

In the United States, color additives used in cosmetics are regulated by the FDA. According to the FDA, henna is approved as a color additive only for hair dye, not for direct application to the skin. Jagua's regulatory status is different again: we are not aware of any FDA approval of jagua or genipin as a color additive for body art, so be wary of any seller who claims their product is "FDA approved." You can learn more from the FDA's color additives and cosmetics fact sheet.

In practice, this means the responsibility for choosing a reputable product, reading ingredient lists and patch testing falls largely on you and your artist.

Choosing safely

Ask what is in it. A reputable artist or seller should tell you the ingredients plainly.
Watch the timeline. Jagua and henna both take a day or two to reach full color. Instant black is a red flag.
Patch test first. Even genuine jagua and henna can cause reactions in a small number of people. See our patch testing guide.
Skip damaged skin. Avoid cuts, rashes, sunburn and freshly shaved areas.
Act on symptoms. If itching, swelling or blistering appears, wash the area and see a doctor or pharmacist.

Chosen carefully, both jagua and natural henna are beautiful, low-commitment ways to wear body art. The key is knowing which is which, and steering clear of anything that only pretends to be either.