Sedr, Senna, and Henna: The Trinity of Herbal Conditioning
Sedr, senna, and henna are three of the most common herbs used to condition hair naturally. I’ll break down each of these herbs, by what mechanism they condition, how long it lasts, and debunk a few myths along the way.
The short version
- Sedr- The leaves of this plant have a permeable waxy coating to help retain moisture. It is the fatty acids and secondary alcohols of this epicuticular wax that gives Sedr its conditioning and cleansing benefits. As such, it will wear off over time and needs to be refreshed every 4-8 weeks.
- Senna– The conditioning properties and golden color come from Chrysophanic acid. The tannins and chrysophanic acid in senna also have anti-fungal and anti-bacterial properties. Needs to be refreshed every 4-8 weeks.
- Henna– There are two steps in the conditioning properties of henna. The first is the lawsone molecule, which binds to the keratin in hair and permanently makes makes hair red-orange, stronger and thicker. Also a desert plant, henna leaves a permeable coating on hair similar to that of Sedr’s. This coating fills in rough spots on the cuticle and helps reduce damage from outside sources such as combing and styling. This permeable coating, however, fades after 4-8 weeks.
The Long Version
Sedr (Zizyphus spina christi)
Zizyphus Spina Christi (Sedr) is an evergreen tree or plant native to northern and tropical Africa, Southern and Western Asia. When dried, powdered, and mixed with water, it produces a mud that conditions hair without any discernible pigment deposit. This makes it an ideal candidate for white or very pale blonde hair. It provides body, aids in detangling, conditions the scalp, and provides shine/sheen to hair.
Like many desert plants, Sedr produces a waxy coating on its leaves to help retain moisture. These epicuticular waxes of plants contain alkanes, alkyl esters, fatty acids, primary and secondary alcohols, diols, ketones, and aldehydes (all things good for your hair). Fatty acids and secondary alcohols are both common ingredients in commercial conditioners. It should be noted that this particular type of plant wax is a relative of latex, so if you’re allergic, be sure to patch test!
While it’s common for hair to be a little fluffy a day or two after rinsing out sedr, it will settle down and hair will be shiny, voluminous, and feel thicker. Some users may find that Sedr is a little drying. Eilistraee combines Sedr with organic aloe vera powder, nettle, and wheatgrass to mitigate dryness while providing extra conditioning and scalp-soothing benefits.
Senna (Senna italica, Senna angustifolia) / Cassia Obovata
Senna (Senna italica, Senna angustifolia) is often referred to by the outdated (science decided on a more accurate name) name Cassia Obovata, or the totally incorrect “neutral henna.” This golden-staining herb is often found in lighter red to golden-red blends. While the name “neutral henna” is misleading, it does share some similar conditioning properties. Unlike henna, however, any conditioning or color imparted from senna tends to fade after a month or two.
Senna’s conditioning properties and golden color come from Chrysophanic acid. The tannins and chrysophanic acid in senna tighten the cuticle, making smoother and shiny. It also has anti-fungal and anti-bacterial properties which are used topically to treat eczema and psoriasis, making it beneficial to the scalp, too. Refined chrysophanic acid is used to formulate topical eczema medications.
You’ll find Senna in many of our natural herbal hair colors including: Sarenrae Golden Blonde, Rusalki Strawberry Blonde, and Fire Genasi Copper. A key difference with NightBlooming’s golden-based blends, however, is the addition of Senna alexandria.
Often pitched as the ‘wrong’ senna compared to Senna italica, I tested a promising source of Senna alexandrea and found it had even higher levels of Chrysophanic acid when compared to Senna italica.
|That’s Senna italica (commonly called cassia obovata) on the left and Senna alexandrea on the right, mixed with warm distilled water and applied to white mohair for 2 hours.|
I was a little skeptical when I investigated this, but I was happily surprised to find that not only did the Senna alexandrea produce great stain, but the mud also had a gel-like consistency, much like one finds with henna. This means that, for example, Sarenrae (which is a blend of Senna italica and Senna alexandrea) will have more color and conditioning properties than Senna italica alone, even before factoring in the other beneficial herbal ingredients (chamomile, horsetail, aloe, and nettle, to name a few).
Henna (Lawsonia inermis)
There is only one true henna plant, Lawsonia inermis. Although it is sometimes called “red henna” it is the only henna. Other herbs have gained misleading names such as “black henna” or “colorless henna.” Don’t be fooled, henna is only one plant and the only color it stains is orange-red. Any natural hair color claiming to be henna that isn’t a shade of red has something else added, either other herbs, or in the worst case, undisclosed chemicals.
The henna bush grows in Africa, southern Asia, India, and other hot, arid zones. This flowering plant has been harvested for centuries for its leaves, which are collected, dehydrated, ground, and sifted into a fine powder.
When henna powder is prepared with a liquid, dye is released from the leaf powder, turning the herbal mud from green to brownish-red. The henna dye molecule, lawsone, bonds with protein permanently binds with protein, for example, the keratin (a protein) in your hair, through a process called Michael Addition. The lawsone molecule is what both gives henna its conditioning properties and its red-orange color. This is where the staying power of henna’s conditioning and strengthening properties comes into play; the permanent nature of this bond also means that the conditioning benefits are long-lasting.
There are two steps in the conditioning properties of henna. The first is the lawsone molecule itself, and its benefits last for virtually-forever (unless you’re one of those rare, magical unicorns for whom henna doesn’t stick). The way in which lawsone binds to the keratin in hair permanently makes hair stronger and thicker. Henna also leaves a permeable, plant-wax coating on hair, similar to that of Sedr. This coating does not lock out moisture, but does fill in rough spots on a cuticle, helping reduce damage from outside sources such as combing and styling. This permeable coating, however, doesn’t last forever and often fades after a few weeks.
Coloring and Conditioning are Inseparable
I’ve read multiple post by people asking about ways to use henna for its conditioning properties without getting the color and the short, final answer is that you can’t. If you want all the perks of henna and none of the color, you’re out of luck. However, you should consider Senna or Sedr instead, even if their benefits are temporary. Never risk using henna if you don’t want the color because once the lawsone binds to your hair, you’re going to have a hell of a time getting it back out (assuming you even can).
Mixing and Matching for Maximum Benefit
Knowing what you do now, you’re able to blend multiple conditioning properties. Using Sedr or Senna to dilute henna will produce lighter hues, while also imparting their unique conditioning benefits. For conditioning with little to no color, a blend of Sedr and Senna works well.
If you’ve hennaed and don’t want your color to darken, but want a refresh of the additional, temporary, conditioning benefits, you can use Sedr or Senna on the length for a refresh.
Want to learn more about herbal hair coloring?
Coloring Hair Naturally with Henna & Other Herbs will walk you through constructing, blending, applying, and rinsing your own herbal hair colors. More than 300 pages of text, pictures, charts, diagrams, and recipes make Coloring Hair Naturally with Henna & Other Herbs the definitive resource for natural hair coloring.