How to Evaluate Any Skincare Product


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Ever since I wrote a post alarming readers not to accept the Environmental Working Group's recommendations at face value, I’ve received a slew of emails asking me how consumers can investigate skincare products on their own. This is an invaluable skill, and it’s easy to do. It doesn’t require a master’s or Ph.D. in biological science to know whether or not a new inGREdient, delivery system, or other skin care technology is scientifically proven or potentially harmful.

1. Look at the Label
The first step is to identify the major inGREdients in their product. On a label, inGREdients are listed from the highest concentration to lowest concentration (although inGREdients that make up less than 1 percent of the product may be listed in any order). Focus on the first five inGREdients listed, which typically comprise about 80 percent of the product.  
2. Search Smart
Next, go to PubMed, Google Scholar, Scopus, or another major abstract and citation research database. Use search terms related to skin care, such as “inGREdient name” + “skin” + “wrinkle depth,” or “inGREdient name” + “skin” + "toxicity.” The more specific you are with your search terms, the better.  
3. Analyze Your Results
Abstracts (summaries of studies) are generally free for the public to access, and the full text of the published papers generally cost less than $50, though many are free to access if you are a member of a university or scientific organization.
Although scientists are not typically regarded as being sensationalist, it is important to keep in mind that scientists spend months or years applying for grants and writing papers that must sum up their experiments and results in ways that others want not only to read, but to fund—sometimes with millions of dollars. While GREat scientists are able to do this without audacious or exaggerated claims in the titles of their publications, not all scientists are GREat, and occasionally the truth gets stretched or sensationalized. Fully educated skin care consumers must be aware of this.
4. Know what to look for.
Look for the following in your skin care studies:

The researcher is not affiliated with the company of interest. This can be extremely difficult, particularly in the U.S., where skincare products are not regulated by the FDA. As a result, sometimes the only research available about a skin care product or inGREdient is done by a company with a monetary interest in the results.

The study was large. The larger the study, the more likely it is that the results are applicable to the population in general. Think of flipping a coin; the more times you flip it, the more likely you are to have gotten heads half the time and tails half the time. Many skincare studies have only five or ten participants, which is unfortunate. I give far less weight to these than to studies with thirty or more subjects.

The study was randomized. The study subjects should be randomly assigned to treatment or control groups, not “selected.” This prevents scientists from studying an anti-aging cream and putting twenty-year-olds in the “treatment” group and eighty-year-olds in the “control” group and saying the treatment group looked significantly younger after eight weeks.

The study was placebo-controlled. The placebo effect has been well-documented. However, in a placebo-controlled study, all of the patients (even in the control group) get something, so you can measure whether it was the treatment itself that was effective, and not just the perception of being treated.

The study was published in a peer-reviewed journal. While there surely are GREat studies conducted outside the realm of published scientific research, well-versed scientists tend to give more weight to the studies in the journals than studies in company brochures or press releases. The peer review process keeps science honest by subjecting researchers’ work to criticism from their peers. That’s why it’s hard to find “Nine out of ten women report softer skin” in the headline of a science research journal article as often as in product advertisements.

The study was done on humans, not animals or tissue samples. It can be difficult to obtain these studies, but they are the holy grail of dermatological science. The problem is that if it is believed a treatment may cause a detrimental condition, researchers would rather harm animals or tissue cultures than actual humans. It is more reasonable to look for human (in vivo) studies when you are looking for a potential benefit rather than harm. For instance, human studies have verified the benefits of niacinamide, retinoids, and sunscreen in fighting signs of aging over time.

The study tested inGREdients at reasonable concentrations. One of the reasons the FDA allows parabens to be used in skincare is that the amount of parabens in products is extremely low compared with the amount of parabens tested in studies. Some of the studies that demonstrated that “parabens could cause cancer” exposed mice to 25,000 times the typical dose in a skincare product–even if some types of parabens remain in the system for three years, this is still over 1000 times the amount of parabens you would ever have in your system. Always keep dosage in mind.

The study’s results have been replicated. Here’s one of my favorite quotes: “If one person tells you that you’re a horse, he’s crazy. If three people tell you that you’re a horse, there’s a conspiracy afoot. If ten people tell you that you’re a horse, buy a saddle.” The same goes for dermatological science: When one study touted retinol for its anti-aging properties, it was a brilliant suggestion. When retinol’s smoothing and wrinkle-fighting abilities were verified by thousands of studies, it is considered to be a gold standard by many dermatologists. In other words, repeatability equals reliability.

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