Natural Surfactants - About Saponins

No sooner than the series about shampoo ingredients is winding down (still have a final installment to do), I find myself face to face with a new (to me) and exciting lathery ingredient that is literally plucked from a tree!

It would appear I am meant to be surrounded by surfactants just a little bit longer. Therefore, I hope you will journey with me into this next (somewhat shorter) mini-series that examines a couple of all natural, plant-based cleansers.

Our story begins in India....

Pleased To Meet You

Not too terribly long ago, I was introduced to a small, wrinkly, brown fruit from India that could clean everything from the most delicate silk undergarments to downright dirty dishrags. I discovered – to my surprise and delight – replacing detergent with a small handful of these berries was not only an effective, easy and inexpensive way to do laundry, it was also a heck of a lot more planet friendly. This amazing little fruit is known as a soapnut (or soap berry).

I Think I Know Your Cousin

I wanted to know more about soapnuts, and started researching. I was convinced they were somehow related to soapwort (an herb I use in a few of my cleansers).

As it happens, soapwort and soapnuts aren't related, but come from 2 entirely different plant familes. But they do have one thing in common – a natural content of saponins.

Saponins – Put Simply

Saponins are a class of chemical compounds that are found in a wide variety of natural sources (for example: plants). The 'sapo' part of the name is Latin and means – you guessed it – soap.

Saponins dissolve readily and will magically make foam when simply mixed with water and agitated. How can they do this? Because they contain both a hydrophobic (water-hating) sapogenin (non-sugar part) and a hydrophilic (water-loving) glycoside (sugar part). In short, saponins are natural surfactants.

All Natural = Perfectly Safe, Right?

Even though we are talking about natural soap, saponins aren't all mellow and mildness. They are toxic to a variety of organisms (some bacteria, fungus, other plants, animals). In relation to humans, saponins are categorized as 'mildly poisonous' (when ingested).

As for topical use, I haven't run across any warnings – quite the contrary. For example, the saponins in the soapnut are said to help battle dandruff and psoriasis when applied topically.

They're Everywhere!

There are a plethora of sources for saponins: plants, marine organisms (some sponges), panax ginseng (of all things!), horse chestnut – even Aloe Vera contains saponin. There are also saponins of a more toxic variety to be found. These are appropriately named sapotoxins.

Fishing With Saponins

Because saponins are poisonous to fish, they have been popular throughout history for poison fishing. Fisherman who used this method needed to be careful to poison the fish without giving tummy aches to the people that subsequently prepared and ate them. (If you think this sounds like a cool and easy way to go fishing, think again – this practice is now outlawed).

What Else Are They Used For

Besides being efficient natural cleansers (and stun-guns for fish), saponins have a surprising variety of uses. Even though they come with a warning, dried saponin-rich plants such as soapwort are sold with instructions on how to brew and serve as a tea to aid digestion. I have seen a packet recently in a drug store in Denmark, and couldn't help but notice the instruction 'not to exceed 4 cups a day' on the label.

Aside from tea, saponins are regularly enjoyed by many a beer drinker. They have been used for generations by manufacturers to help make a frothy foam head and are still present in some brands today. 

Next Time it's All About Cleansers

Now that you are saponin savvy, next time I'll get into a bit of detail about 2 of the natural surfactants I have been working with – both for skin care and laundry.


Leslie said…
That is fascinating. You are an awesome researcher! Thanks for teaching me so much more about saponins (and soap nuts!).

Also, I had NO idea that they were used in beer brewing. Haha. I'll have to ask Skip if they use saponins in the beers at his brewery. They do tons of "old-fashionedy" stuff there. So if they don't, maybe they will for one release. Coolness!
LisaLise said…
Thank you Leslie. I almost can't help myself with the researching when I get curious about something, and your wonderful soapnuts posting got me started. Look forward to hear about the brewery!!
Anonymous said…
Gr8 post!!! I m from India..soapnut is used along with shikakai and amla for bath since last few thousands year...
LisaLise said…
Thank you Anon - I have been working with Amla for a while and will now ne looking into shikakai. :)
Shia said…
So are these soap nuts which contain Saponin ,that is considered to be toxic ,
safe to wash your hair everyday? I mean can the toxins get absorbed through your scalp and have bad consequences?
LisaLise said…
Hi Shia - Soapnuts are only poisonous to fish. You can use soapnut decoction daily as both skin and hair cleanser without worry. Be careful not to get any liquid in your eyes though as it will sting the eyes. Because of this, it is not recommended to use soapnuts as a shampoo for young children.
Sarna said…
hi there, can you suggest me of a natural saponin which only cleans hair and body skin but does NOT lighten my skin complexion and which does NOT make hairs grow longer or thicker or straighter or curlier or darkar or lighter but only cleans them and also which I can find in India?

-Thank You
LisaLise said…
Hi Sarna - Not from India, but my best suggestion here is pure rhassoul clay. It cleanses hair and skin gently and effectively without drying or whitening or anything else. Can you source this? It is from Morocco.
Sarna said…
hiiii ☺☺ thank u so much for ur reply. I may find the clay online i guess.My only concern is if it lighten skin by any chance at all ? And will it straighten my hairs ? I know I'm asking it again but this is my only concern. Because when i searched for the clay, i found out that it evens skin tone.
LisaLise said…
HI Sarna - Pure rhassoul clay will not straighten hairs or lighten skin-- it cleanses gently and effectively. I have written a few blog posts on it. Try the search button at the top and type in rhassoul to find them. Best of luck!
sarna said…
thank u so much 😊
Unknown said…
Lise, amazing as I was researching how saponins affect the skin as our oil of the month Pracaxi (February 2020) contains saponins and I was curious how that made this oil so unique. Thank you! Your post is helping me unravel the properties of the oil.

LisaLise said…
Yay! Thank you for your kind comment — loving the oil of the month membership 😃