Bakuchiol is an active ingredient launched in cosmetics 13 years ago, at a time when genomic and proteomic analysis methods were very much in their infancy in the world of cosmetics. Yet they were already being used to identify the potential that this meroterpene represented as an alternative to retinoids.

Eight years and a number of publications later, the reputation of bakuchiol has gone from strength to strength, to the point of finding itself at the center of a media frenzy at the start of the year that saw it reach quite a unique level of popularity in the history of cosmetic ingredients.

An analysis of Google Trends data shows that the number of searches for this active ingredient had simply sky-rocketed, accompanied by an increase in the number of articles in women’s magazines such as Glamour and Elle and YouTube videos about the ingredient. Market research specialist Mintel even named it one of the trendiest ingredients of 2019 and beyond, but what is bakuchiol and why is it attracting so much attention?

 

 

Bakuchiol fact sheet

 

The Psoralea corylifolia plant endemic to certain Asian countries such as India and the Himalayan regions of Pakistan and China is a wild species that has been used in Ayurvedic medicine for centuries. It is known by various names, including babchi or babachi in Hindi, ravoli in Sri Lanka, boh‑gol zhee in Korean and buguzhi in Chinese (1), and has notably been used to treat vitiligo. It was only in 1966, however, that G. Mehta et al. characterised and isolated one of the main compounds of the seeds that they named bakuchiol, after the plant’s Sanskrit name, bakuchi (2).

Having studied bakuchiol for a number of years, Sytheon was the first company to commercially market a very pure grade of the ingredient, produced by means of a complex molecular extraction process, in the cosmetics industry under the Sytenol® A brand name in 2007.

The main reason for this isolation stemmed from the high furocoumarin content of the seed, the two main ones – psoralen and isopsoralen – giving the plant its Latin name long before it was identified as bakuchiol.

 

Thanks to a monomolecular extraction process, Sytenol® A contains over 99% bakuchiol and a combined total of fewer than 25ppm of psoralen and isopsoralen. The REACH-registered mono-compound has been the subject of various specific toxicological and ecotoxicological studies and is incorporated in products developed by over 150 brands worldwide.

As well as being both natural and vegan, this cosmetic active ingredient is also a powerful antioxidant with anti-inflammatory properties that has been clinically proven to have anti-ageing and anti-acne properties to boot.

 

 Bakuchiol and its potentially retinol-like properties

 

Since Kafi et al.’s May 2007 publication on the anti-aging effects of a solution containing 0.4% retinol on aged skin (3), the alcoholic form of vitamin A has become the ultimate benchmark in terms of cosmetic anti-aging products, initially for the medical community and later for the general public. That said, as is the case with many active molecules, the side effects that it has been found to have, such as irritation, bad reactions and photosensitivity, and in particular its stability over time when incorporated in a formula, have proven to have a detrimental effect on the use of retinol and its analogues. Many of the active ingredients in the anti-aging market claim to have retinol-like properties, but how does an active ingredient come to be considered as an alternative to retinol?

A comparison of bakuchiol and retinol molecules reveals that there is no structural similarity between the two. In functional terms, however, genomics has helped to highlight some surprising similarities between bakuchiol and retinol (4), whilst proteomic data and biological studies on a large number of enzymes and proteins have consequently confirmed these pre-transcriptional functionalities, including the renowned clinical study by UC Davis published in the British Journal of Dermatology in June 2018 (5).

 

 

The student surpasses the teacher

 

The University of California performed a double-blind clinical study on 44 volunteers comparing bakuchiol and retinol, both used in a cream at the same concentration (0.5%). The study showed that the two active ingredients performed similarly in terms of photoaging (59% reduction in hyperpigmentation after 12 weeks), although bakuchiol is much better tolerated by the skin, particularly when it comes to stinging and desquamation (significant differences in comparison with retinol). UC Davis ultimately concluded that bakuchiol could effectively improve the signs of aging in the skin and Sytenol® A is one alternative that is better tolerated by the skin than retinol.

 

The media coverage can, therefore, be clearly explained by the comparison with super-star retinol, both the virtues and the restrictions of which any specialist will be familiar with. Achieving blockbuster levels of performance without displaying the known side effects is already enough of an asset to attract international interest within the beauty blogosphere, which is always on the lookout for new developments and eager to discover the miracle product.

That said, the fact that this is a natural alternative to a synthetic compound has also clearly contributed to the buzz surrounding the ingredient, at a time when the natural aspect of a product has become almost a pre-requisite, regardless of the fact that this does not guarantee its harmlessness.

Brands that use bakuchiol have indeed benefited from the various references made by many bloggers, influencers and beauty journalists online, but the distinct appetite of the ‘organic bohosphere’ for natural, unrefined products also has its idiosyncrasies, with some bloggers taking the recommendation beyond reliable brands that are subject to strict cosmetic regulations. The showcasing of so-called ‘more natural’ alternatives such as the both organic and non-organic babchi or bakuchi oils sold on Amazon and other e‑commerce sites has consequently resulted in a partial deflection away from the use of tested and certified cosmetics in favour of imported products that do not comply with the relevant regulations and are dangerous to consumers.

It is also important to note that few products offer any indication with regards to the use or indeed properties of the product.

 

 

Babchi oils called into question

Herbs forever USA (babchi oil)
HPLC (% w/w)
6.8
Psoralen and Isopsoralen content determined by HPLC (ppm)
3066
Residual solvent CG (ppm
-
a. Methanol
17
b. Hexane
2235
MB Herbs cold pressed Bakuchi oil
HPLC (% w/w)
1.6
Psoralen and Isopsoralen content determined by HPLC (ppm)
1003
Residual solvent CG (ppm
-
a. Methanol
2
b. Hexane
0.4
JK Herbals cold pressed Bakuchi oil
HPLC (% w/w)
1.7
Psoralen and Isopsoralen content determined by HPLC (ppm)
989
Residual solvent CG (ppm
-
a. Methanol
1
b. Hexane
1
EC Aurous babchi oil (lot# BAB-108)
HPLC (% w/w)
12.1
Psoralen and Isopsoralen content determined by HPLC (ppm)
4768
Residual solvent CG (ppm
-
a. Methanol
47
b. Hexane
1900

Four commercial products purchased from Amazon were analysed at our laboratories to establish their purity, their furocoumarin content, and any residual solvents that they might contain. CLHP bakuchiol doses resulted in bakuchiol values ranging from 1.6% to 12.1% in relation to the standard Sytenol® A, with psoralen-isopsoralen levels ranging from 1,000 to 5,000ppm – far exceeding the IFRA recommendation of 1ppm max. in finished products!

Analyses of 4 commercial Babchi oil

 

Even with the intention of using them at a concentration of 10% in a plant-based oil of the consumer’s choice, the marketing of natural oils, both cold-pressed and otherwise, exposes the user to the risk of furocoumarin doses that far exceed the acceptable thresholds. The grades with the highest bakuchiol content (Herbs Forever USA and EC Aurous Babchi Oil), at 6.8% and 12.1% respectively, are methanol and hexane-extracted, with residual content ultimately leaving around 200ppm of hexane on the skin and 300-500ppm of furocoumarins.

 

 

Conclusion

 

The public’s perpetual distrust of brands that they consider to be industrial in favour of exotic artisan products inspired by Ayurveda and other forms of traditional medicine often results in recommendations that appear somewhat contradictory with regards to consumer safety. The industry has been striving for decades to meet increasingly strict regulatory standards and even, in many cases, exceeding them with its own internal quality requirements that exceed those imposed by the law. That said, responsible cosmetics brands remain at the mercy of perception and find it difficult to communicate with the general public, which tends to be more inclined to believe whistleblowers and natural and organic radicalists.

Nature may well inspire research but it doesn’t always offer a one-stop solution, and it is important that this trend for all things natural bear in mind that a full analytical characterisation, standardisation and comprehensive toxicological data content are pre-requisites where any substance is concerned, be it natural or synthetic.

 

References
(1) Uikey SK, et al. Intern J Phytomed 2010;2:100-7
(2) Bakuchiol, a novel monoterpenoid G. Mehta, U.Ramdas Nayak, Sukh Dev ; Tetrahedron Letters ; 1966
(3) Reza Kafi Arch Dermatol/Vol 143, May 2007
(4) RK Chaudhuri & K Bojanowski. International J Cosmetic Science, 36(3) :221-230, 2014
(5) Dhaliwal et al., British J Dermatology, 2018 Jun 27. doi: 10.1111/bjd.16918