There has been much written about the benefits of herbal and plant extracts in cosmetic products. You can find entire books like this one and this one dedicated to expounding on all the great things plant extracts will do when incorporated into a cosmetic formula. There are numerous magazine articles, volumes of supplier literature, and even entire conferences about botanicals in cosmetics.
But you know what you don’t see very often?
The truth about formulating with natural extracts. You never get to hear the gritty reality behind herbal extracts, what they are, what they do in formulas and how the industry actually uses them in product development. That is what this article is meant to do. This article is also meant to be for cosmetic formulators who are serious about using science to drive the development of their cosmetic products. I’ll leave the marketing stories for the raw material suppliers, finished goods manufacturers, naive DIYers, and internet self-taught formulators.
What are botanical extracts?
In essence, botanical ingredients those derived mainly from plants, although microbial and even animal derived materials get lumped in there too. Botanicals also go by different names such as herbal extracts, plant extracts, hydrosols, tinctures, distillates and they are derived from plants in different ways.
An herbal extract of pretty much any plant you can imagine is available. They come from all parts of the plants including the leaves, stems, roots, flowers, fruits, etc. You can get them from a direct supplier like Carrubba or a distributor like MakingCosmetics. They are typically supplied as solutions of the extract in a solvent like propylene glycol which is one of the main reasons you find propylene glycol on the label. It’s a good cheap solvent for extracts. Other solvents include glycerin, ethanol and water.
Hydrosols, essential oils & extracts
There are a few different types of ingredients you can get from plants depending on the part and type of plant that you use. One way that natural ingredients are processed is through steam distillation. This is how you can get both essential oils and flower waters, also called hydrosols. In the distillation process, the plant material if put in a kettle and steam is run through it. Any material that is volatile will break away from the solid mass and be sent with the steam to the distillation tube. As the ingredients are cooled down through condensers surrounding the distillation tube, they become liquid again and are gathered in a separate kettle. The oil soluble materials will separate from the water soluble materials resulting in essential oils and hydrosols.
The hydrosols are primarily made up of water but will have some floral ingredients that are soluble in water. There is typically less than 5% plant matter in a hydrosol. It’s worth mentioning that in general, hydrosols are not ingredients used in mainstream cosmetic formulating. They are more of an ingredient that a person who does formulating as a hobby or an indie brand might use. The reason is that these ingredients are difficult to produce consistently and they do not remain stable for long enough. They might work fine on a small scale but they don’t scale up.
Composition of botanical extracts
Thus far we’ve discussed the way extracts are obtained, but the theoretical usefulness of these materials comes from the chemicals of which they are composed. This list is not comprehensive but typical chemicals found in these extracts include
Alpha Hydroxy Acids
There may also be mineral ions like potassium, magnesium, calcium or others found in the extract.
Herbal extracts can be made up of dozens or even hundreds of different ingredients. This complexity is great for finding different materials that might be beneficial for people, but it also hints at some of the biggest problems with using extracts.
Primary problems of formulating with extracts
Since you’ve probably heard all the great things herbal extracts are purported to do, let’s focus on the problems with using them. There are a number of problems formulating with plant extracts but the main ones include
Perhaps the biggest hurdle to creating formulas using botanical extracts is the lack of consistent supply. Since herbal extracts are derived from plants the exact composition will vary depending on the growing conditions of any particular crop. This means even if you buy your extracts from the same supplier you won’t get an ingredient with exactly the same chemical makeup. In many cases this won’t matter, but if you are relying on your extract to act as the functional ingredient in your formula, often you will be disappointed.
It’s like trying to make a cake where you don’t know the exact amount of sugar that goes in. Sometimes you’re adding a teaspoon while other times you’re adding a cup. The final product would just perform inconsistently and cause quality control problems that aren’t easily solved. When consumers buy cosmetic products they expect a product to perform the same every time. When it doesn’t, they don’t tend to buy it again.
And related to this supply problem is that when you purchase an herbal extract you have no way of knowing the exact composition of the material. There are some tests you can run such as pH, color, and IR Spectroscopy, but these can’t possibly give you the level of detail needed to identify all the components and percentages in a sample. On some level you really have no way of knowing exactly what you are buying. Without a complete specification sheet a supplier could easily substitute one plant extract for another and you would be none the wiser.
An example of this actually happening is when some formulators were using “Grapefruit Extract” as their main preservative. It worked, but only because the extract had been spiked with the real, synthetic preservatives Benzethonium chloride, Methylparaben or Triclosan.
The bottom line is that mainstream companies cannot rely on nature or raw material suppliers to provide them with herbal extracts that are consistently the same quality or composition. So, they don’t. Instead, they use tiny amounts of these compounds such that there are no negative (or positive) impacts but can they can still talk about them in their marketing materials. Those stories of performance are a huge selling point for products with herbal extracts, but as you’ll discover these are mostly exaggerations.
While stories about the benefits of botanical extracts abound, the reality is that these ingredients don’t perform nearly as well as advertised. In fact, in the vast majority of cases herbal extracts are nothing more than cosmetic claims ingredients used to support the stories that marketing people tell to sell their products. I can’t go through the details of all the research that has been done on all the herbal extracts but in general support for their use comes from two sources, traditional use and laboratory studies.
A number of natural ingredients have been used throughout the centuries as herbal medicines and treatments. Anecdotal evidence of their effectiveness was all the proof people needed to keep using them. But the use of these things started before the scientific method was developed and it turns out, many of the things that were used for a long time did not actually have the benefit for which they were used. When subjected to the scientific scrutiny of a double-blind, placebo controlled test, these ingredients are typically found to be ineffective. For example, castor oil for growing hair or lemon juice for treating acne. Neither of these work.
Irrelevant lab studies
Of course, a number of natural ingredients can be shown to be effective…in laboratory studies. The problem is that usually these lab studies do not translate to positive effects when used in real-life products. Just because an ingredient shows a benefit when applied directly to human skin cells in a petri dish does not mean it will have any effect when delivered directly to the skin from a lotion or other personal care product. Until there is a placebo controlled, double blind study, we should assume an ingredient is not having a noticeable effect.
But getting that kind of evidence is hard and marketers are under a lot of pressure to launch new products based on new technology. So once an ingredient shows any promise in the lab, raw material suppliers and marketers alike start telling the story that the ingredient is going to make the product work better. Almost invariably, it doesn’t.
Bakuchiol in cosmetics – a case study
Let’s look at a recent example of an herbal extract getting a lot of good press, Bakuchiol. This is an extract derived from the babchi plant (Psoralea corylifolia) which has traditionally been used in India for Ayurveda treatments. It is popular because it has been suggested it could be an effective alternative to retinoids. Retinoids have been shown to have good anti-aging effects in skin care and can even work on acne. Well, in a couple recently published studies, Bakuchiol has been shown to match the effectiveness of retinol for skin aging. This ingredient has gotten a lot of attention because while retinols are effective anti-aging ingredients, they are also irritating to a lot of people’s skin. The Bakuchiol extract is said to be effective without the irritation.
This means a lot of people who can’t use retinol because of the negative side effects might be able to get similar effects using bakuchiol. But the reality is that the data supporting its use is pretty weak. There are only a couple of studies, on a small number of subjects, or on human skin cells and they haven’t been replicated. Retinoids have decades of solid research behind them. This ingredient, not so much.
Now, it may turn out that Bakuchiol is effective but even if it is, this points to one of the other performance problems with plant extracts, using them is inefficient.
The claimed benefits of plant extracts are often things like anti-oxidant, anti-inflammatory, sun protection or repair, or protection from hyperpigmentation. They may even make more direct drug claims like wrinkle reduction, hair growth, cellulite reduction, collagen stimulation, or anti-acne. The problem with these claims is that if the ingredients actually were shown to have this effect, that would make them illegal, unregulated drugs in the US and many other places around the world. So, the only way they can be legally added to a formula is if they don’t actually have the drug effects that are often implied, or directly claimed. If topical CBD is really an anti-inflammatory, that makes it a drug which is currently illegal to sell in the US.
Now that we’ve covered the supply problems and performance problems, let’s look at the formulation problems with botanical extracts.
Most of the cosmetic and personal care products produced today are at least in some part water based. And if you are using an extract in a formula that contains water, you’re going to need to work extra hard to find a preservative system that works. This is because natural extracts are filled with natural microbes both living cells and spores which can grow into living cells under the right conditions.
Additionally, the complexity of natural extracts means there are numerous chemicals that can interact with other ingredients in your formula which may ultimately cause stability problems such as color changes, odor changes, performance problems or product separation. Formulating with extracts is just much harder.
One other issue in formulating with extracts is that using them is not an efficient way to formulate. While some extracts might have an effect in a formula, the actual benefits come from some chemical in the extract which generally makes up only a small percentage of the whole extract. Typically what happens is you identify the chemicals that are really effective from the extract, isolate them, and reproduce them synthetically for much less money. This is already done in cosmetics and drugs and is how we’ve gotten a number of effective raw materials. Using extracts to deliver tiny amounts of effective ingredients is just an expensive way to do something that can be done for less. Also, using a synthetic knock-off of the functional part of an extract means you can have a more consistent result without worrying about the supply problems outlined previously.
The final problematic area with using botanical extracts in formulating is the issue of safety and irritation. The majority of botanicals and herbal extracts contain chemicals in them that cause allergic reactions or skin sensitivities in many consumers. Certainly, the percentage of the population that has a reaction to these ingredients is not usually high but it is significant. It’s just a reality that plants evolved compounds that cause problems for us as a way of defending themselves. Poison ivy produces a nature oil component that you don’t want to get on your skin. In fact, the vast majority of common ingredient allergens are derived from natural, plant-based ingredients.
Natural Extract Use in cosmetics
Despite the problems outlined natural extracts remain popular ingredients in cosmetic products. The allure of the stories they allow marketers to tell is just too strong and it is undoubtedly effective in getting consumers to buy products. Since consumers already have beliefs about certain ingredients, marketers can talk about them in their products without having to make any unsubstantiated claims. This is a win for them and consumers believe they’re winning too. The fact that the extracts don’t actually do anything doesn’t seem to matter to anyone.
Final word on herbal extracts
In summary, in the cosmetic industry extracts are added to cosmetic products at low levels just so companies can tell a story. They aren’t expected to do anything in a formula. Cosmetic chemists working in industry know this and incorporate them in formulas accordingly. Unfortunately, there are a number of “natural” or “green” formulators who use motivated reasoning to find reasons to include extracts into their formulas. That means there is a lot of formulation advice to be found online through social media, blogs, and YouTube that ignores the very real problems of herbal extracts and propagate marketing myths of botanicals. You can even get a number of diplomas in the subject. But getting a diploma or following marketing myths won’t make you a better formulator. To do that, you’re going to have to discover the real “benefits” of herbal extracts yourself.
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