The first thing to keep in mind is that “peptide” is really far too vague a term in this context. A peptide is just what we call a short chain of amino acids. Add together these chains, and we get a polypeptide. Arrange these polypeptides in specific formations, and we get proteins. In essence, an amino acid is a single building block of a protein—a brick, if you will. A peptide is a row of bricks, and a protein, for the sake of this analogy, is like a wall. So asking if peptides will help your hair isn’t a great question, because it depends entirely on what that peptide is—what are the individual “bricks”? What happens when we put lots of rows together? What kind of wall are we building? The problem with products that claim to use peptides to improve your hair is that these questions generally are going unanswered. That’s not to say that these companies are being duplicitous—the fact of the matter is that the average person is not going to understand anything more specific than “peptide”. In fact, the average person probably has a very limited understanding of what a peptide is at all, so the use of the term for advertising purposes is really just to pique interest and garner trust purely on the basis of the product name sounding scientific. After all, we want to believe that the things we do for our physical appearance are really working! That’s why the latest trend in haircare and skincare is to focus heavily on these scientific buzzwords. So to answer the most basic question—do peptides work?—well, it depends. It’s an ambiguous answer for an ambiguous label.
Fortunately, we’re here to help break down the jargon of scientific journals for you and give some evidence-based answers once and for all. A word to the wise: this is all what we know as of right now, but new—and sometimes conflicting—research is always happening! That’s why it’s so important to keep updated, and to look at the science instead of blindly trusting the product label. That’s also why at Densella, we aim for full transparency by providing links to peer-reviewed sources for your own perusal.
The proper question to ask would be what peptides, specifically, have been shown to work? The great news is that there has been exciting recent research on the topic of peptide treatment in hair loss, with promising results. A 2018 study published in the Journal of Medicinal Food (itself published by the Korean Society of Food Science and Nutrition) found that water-soluble peptides derived from egg yolks are capable of stimulating production of the same growth factor targeted by the drug minoxidil (commonly known as Rogaine). The researchers were inspired to examine the chicken egg for a key hair growth factor after recalling that hair growth in the chicken occurs before hatching, and found that egg yolk peptides induced expression of vascular endothelial growth factor (VEGF). What this means is that when this peptide is introduced, it stimulates a specific pathway to begin coding for the production of VEGF, which in turn promotes growth of dermal papilla cells in the human hair follicle. The study authors have named this egg yolk peptide “hair growth peptide”, or HGP.
You might be wondering at this point what the importance of HGP is if it functions essentially the same as minoxidil, which is much more readily available. There’s nothing wrong with using minoxidil for hair loss—as the most commonly used hair loss treatment in the world, there is an abundance of literature supporting its efficacy. However, minoxidil can lead to such short-term side effects as irritation, eczema, and contact dermatitis, and in rare cases, long-term side effects such as dizziness, irregular heartbeat, and fatigue. Minoxidil is also a vasodilator medication, originally intended for oral use to treat high blood pressure—while most patients are likely to experience such an adverse reaction, it is possible for minoxidil to be absorbed through the skin and cause an elevated heart rate and chest pains. As such, it’s always a net positive for the market to have increased options, so individuals can decide for themselves what risks they’re willing to take. Currently, HGP appears to be far less likely to cause long-term effects than minoxidil.
Now, you might be wondering if it’s worth waiting for haircare products with HGP to show up near you, or if just consuming a lot of egg yolks might do the trick. We’re going to stress here that HGP is a peptide derived from egg yolks, which means there’s a very specific process undertaken to successfully separate HGP from the rest of the yolk. As of now, there isn’t any clinical evidence to suggest that simply eating egg yolks will significantly improve the quality or quantity of your hair. But egg yolks are full of protein and are a great natural source of biotin, which contributes to keratin formation, so it doesn’t hurt to add eggs to your diet (within reason!)
A 2022 study in the Journal of Drug Delivery Science and Technology may soon also make an impact in the haircare space, having found that transdermal (through the skin) absorption of peptides was significantly improved when said peptides were encapsulated in nanoliposomes—a type of vesicle formed from fatty acids. The researchers developed nanoliposomes containing three different peptides: copper peptide, acetyl tetrapeptide-3, and myristoyl pentapeptide-4. Dubbed CAM-NLPs, these peptide-containing nanoliposomes were extremely effective in boosting hair growth when compared with free peptides (peptides introduced on their own, rather than being packaged inside a nanoliposome). What does this mean for the consumer? Well, first, now that you’re aware of the efficacy of free peptides vs. peptides encapsulated in nanoliposomes, hopefully this is a question you’ll have in mind the next time you see a hair product touting its use of peptides—not only which peptides, but the method of delivery. If a company boasts its peptides, check the website for the science. If the information is unavailable, then the decision on whether or not to spend your money on the product becomes harder, but regardless of the choice you make, it’s always better to begin the journey armed with more knowledge.
Your diet guru,
Melissa A.
If you’d like to read through the referenced journal articles in this post, feel free at the below links!