Beginners skin science
April 8th, 2026 by Dr. Hannah Sivak
Below, I describe the properties of some natural chemicals that are used in skin care. If you would like to know about a chemical that is not in this list, let me know, and I will add it in subsequent “editions”. Natural chemicals are those present in nature, in plants and/or animals. The actual ingredient you find in a formulation may be obtained by chemical synthesis, fermentation, or biotechnology; what matters to your body is the chemical structure, not the “origin”. Chemical structure is not just the number of atoms and how they are linked to each other, but also how they are organized in space. I included some references…
February 28th, 2026 by Dr. Hannah Sivak
Coconut milk is an endosperm product that has a growth-stimulating effect on the developing coconut embryo. In 1941, the Dutch plant physiologist J. van Overbeek discovered that the addition of coconut milk led to a marked increase in the growth of plant embryos and tissue cultures. The question of which components cause the growth stimulation arose immediately, and kinetin was discovered. Experimental data indicate that kinetin acts as a strong antioxidant in vitro and in vivo, not only in plants but also in animals. Kinetin has been found to inhibit oxidative and glycoxidative protein damage generated in vitro and to protect DNA against oxidative damage mediated by the Fenton reaction.…
January 6th, 2025 by Dr. Hannah Sivak
Look at the ingredient list below. Has anything changed in 20 years? $300 will buy one ounce (30ml) of this: Algae Extract, Water, Dimethicone, Isododecane, Glycerin, Hydrogenated Polyisobutene, Trisiloxane, Caprylic/Capric/Myristic/Stearic Triglyceride, Vinyl Dimethicone/Methicone Silsesquioxane Crosspolymer, Caprylic/Capric Triglyceride, Sea Salt, Yeast Extract, Everlasting flower (?) Extract, Sesame Seed Oil, Alfalfa Seed Powder, Sunflower Seedcake, Sweet Almond Seed Meal, Eucalyptus Leaf Oil, Sodium Gluconate, Copper Gluconate, Calcium Gluconate, Magnesium Gluconate, Zinc Gluconate, Tocopheryl Succinate, Niacin, Sesame Seed Powder, Red algae Extract, brown algae Extract, Molasses Extract, Phytosphingosine, brown algae Extract, Corallina Officinalis Extract, Sodium Hyaluronate, St. Paul’s Wort Extract, buckwheat Seed Extract, Rapeseed Seed Oil, Polyglyceryl-3 Diisostearate, Licorice Root Extract, brown algae…
January 2nd, 2025 by Dr. Hannah Sivak
What is “stem cell conditioned media (SCCM)”? It’s the liquid that helps maintain and grow stem cells growing on solid support. To keep the cells growing, it has to be discarded (and fresh medium added). Human stem cells may be used for a number of applications, but the old medium has no other use. After all, it now contains stuff the living cells discarded, it has been depleted of chemicals the cells used for sustenance, and its composition is now unknown. The fresh medium is a solution containing all amino acids, sugars, vitamins, etc. that the cells need to live. For convenience, it also includes a pH indicator, to alert…
December 23rd, 2024 by Dr. Hannah Sivak
The problem: To protect your body, the skin has to withstand a constant bombardment by reactive oxygen species, ROS*, from the outside (delivered to the skin by the environment) and generated within the skin itself, either as a response to incident UV radiation or formed when our (amazing but imperfect) mitochondria respire. The antioxidant system in our own cells is very complex, as shown in the following figure. I am including it in a large size so that you can appreciate the complexity of the system. You can see the external (UV, urban particulate matter, noxious chemicals) and internal (imperfect respiration) factors that contribute ROS* and how they damage the…
November 21st, 2024 by Dr. Hannah Sivak
#22: The Role of Growth Factors in Skin Rejuvenation with Dr. Hannah Sivak by The Beauty Beat
October 7th, 2024 by Dr. Hannah Sivak
What does it mean? Science is a process. We learn as we research, and life is complicated. When I started college in 1966, it wasn’t even clear to me how many chromosomes there were in a human cell. Maybe it was because old textbooks still circulated with the old number, 48. Actually, Joe Hin Tjio and Albert Levan reported in 1956 that the correct human chromosome number was 46, not 48, as was supposedly established some three decades earlier. Textbooks are full of errors. Gene regulation determines differences between types of cells, and if it goes off track, it can lead to diseases such as cancer, diabetes, or autoimmunity. Researchers…
September 29th, 2024 by Dr. Hannah Sivak
Please don’t buy the old editions of my books. We will soon have ready a version with simple, updated recipes for you to make at home. This will be the first editorial effort of my post-Skin Actives career, a more mature and realistic view of post-normal skin science! Hannah
September 1st, 2024 by Dr. Hannah Sivak
Oils have become an object of advertising hype in skincare, just like other ingredients. This would not matter much except that different oils can have different effects on your skin. How to choose a good oil for your skin? Think about nourishing your skin and NOT the acne bacteria. Are you looking to alleviate a skin condition like eczema? What matters to your skin is the fatty acid composition and NOT how pretty the name of the plant might be. An oil may contain some beneficial impurities, but some impurities may impart a strong odor. I prefer to use purified oils and add extras as needed. You will be using…
June 14th, 2024 by Dr. Hannah Sivak
Active Ingredients: 15% Zinc-Oxide (non-nano) Inactive Ingredients: Aloe Barbadensis Leaf Juice, Purified Water, Caprylic/Capric Triglyceride, C13-15 Alkane*, Glycerin, Lauroyl Lysine, Polyglyceryl-2 Oleate, Polyhydroxystearic Acid, C12-15 Alkyl Benzoate, Stearalkonium Hectorite, Leuconostoc/Radish Root Ferment Filtrate, Dipalmitoyl Hydroxyproline, Tetrahexyldecyl Ascorbate, Tocopherol, Kappaphycus Alvarezii Extract, Caesalpinia Spinosa Fruit Extract, Melanin, Bisabolol, Hyaluronic Acid, Camellia Sinensis Leaf Extract, Phospholipids, Polyglyceryl-2 Stearate, Sodium Chloride, Propylene Carbonate, Isopropyl Titanium Triisostearate, Titanium Dioxide (C.I.77891), Iron Oxides (C.I.77492, C.I. 77491, C.I.77499) *Our C13-15 Alkane is from Sugar Cane, ECOCERT approved, NPA Certified and USDA Biobased. Incidentally, Leuconostoc/Radish Root Ferment Filtrate is known to be adulterated because it doesn’t contain enough endogenous antibacterial/antifungal chemicals to be used as a…
June 13th, 2024 by Dr. Hannah Sivak
Do I “believe” in aromatherapy? Yes and no. Essential oils contain a mix of chemicals, and it makes sense that some of the chemicals will have an effect on the body. If I can have an allergic reaction to a lavender essential oil (yes, that’s unlucky), why not expect other, maybe even beneficial, effects? But I have a problem: the language used in aromatherapy, full of wishful and magical thinking, puts me off. This doesn’t exclude the possibility that some essential oils are good for you; I was waiting to see some mechanism of action uncovered by scientific research. One of my favorite things is the smell of orange blossoms,…
May 31st, 2024 by Dr. Hannah Sivak
Everything we see seems to indicate that Ozempic and drugs with a similar mechanism of action are here to stay. It’s not “just” for obesity but also for diabetes, and outcomes for heart and renal disease seem to improve. These medications took a long time to arrive, and many patients who benefit from them are older and have been overweight for many years and even decades. You will be able to wear nicer clothes, knee and foot pain may go away, and you can see your body as it used to be when you were younger and thinner. But your skin is now showing its wrinkles, and your arms are…
May 1st, 2024 by Dr. Hannah Sivak
The so-called vampire facials involve drawing a patient’s own blood, centrifuging it to separate out platelet-rich plasma, and puncturing the skin with very fine, short needles. This is said to prompt the skin to produce elastic and collagen and create openings for the plasma, which is applied topically to help with skin repair. The procedure is promoted to reduce signs of aging, acne scarring, and sun damage. There is scant research supporting these claims. Conversely, there is plenty of evidence that “playing” with blood and skin and people’s health can end badly—like with disease and death, perhaps? With apologies to Spider-Man’s Uncle Ben, “with great ignorance comes blood contamination.” The…
April 30th, 2024 by Dr. Hannah Sivak
I would prefer it if we all just gave up on the silly idea that a tan makes us look better. But, if I can’t win, let’s make it less bad than a suntan or a chemical tan. What is a suntan? It happens when UV (it doesn’t have to be the sun!) reaches your skin and starts a cascade of events that ends up with the pigment melanin accumulating in the keratinocytes of your skin. See my posts below for more information. What is a chemical tan? Here, the pigment is not melanin, and melanin has nothing to do with the process. Here, the chemicals in the “cosmetic” product…
April 15th, 2024 by Dr. Hannah Sivak
ROS can destroy everything they find: proteins, DNA, lipids, and life. The environment provides plenty of ROS* (reactive oxygen species), but so does your body! How? Respiration and mitochondria are the main suppliers of usable energy to fulfill all our needs. They produce energy by extracting it from foodstuffs, and electron transport plays a big part in this. However, the electron transport process, a marvel of life, is far from perfect, and ROS* are formed. Our body has the machinery to deal with ROS*, acquired during millions of years of evolution in an oxygen-containing atmosphere. But this machinery, just like everything else in our bodies, ages as we age. Why…
April 6th, 2024 by Dr. Hannah Sivak
And do you need ugly new words? No, but we get them anyway. Slugging is a “viral” skincare technique that involves coating your face in an occlusive moisturizer, like a petrolatum-based formula, to help it heal. It got its name because it makes your face look ultra shiny and slimy—like a slug made its way across your face. If you have severe skin problems, like those caused by diabetes or cancer, your doctor may have suggested an occlusive cream anyway. But what about the rest of us? If you follow social media, you may have already bought petrolatum-based cream (vaseline is a tradename for petrolatum) or maybe a slugging cream.…
April 2nd, 2024 by Dr. Hannah Sivak
Older skin is different from baby skin, not just in texture but also in color. Or, let’s say, colors, like in plural? Older skin looks almost like a map, with different spots reminding you of all the ays we mistreated our skin as we grew up. That burn while we were boiling water in the kettle? The time we stayed way too long in the sun after the sea had rinsed away the sunscreen. How about broken capillaries? They produce bruising that changes color with time and may take months to disappear. You may also get those pin-size red spots. Many illnesses require the use of anticoagulants: heart arrhythmia, cancer,…
March 18th, 2024 by Dr. Hannah Sivak
One of the saddest things about the hair care industry is its inability/unwillingness to use keratinocyte growth factor (KGF), a key tool in hair growth and restoration. The same goes for all those businesses dedicated to “restoring” eyebrows and eyelashes. Another problem is that humans’ pursuit of immediate gain often goes together with an inability to appreciate the future. When a teenager uses heat or oxidants to push her hair in today’s fashion directions, she is also damaging her hair follicles. But who cares about what will happen in 60 years? The 75-year-old will care, and let’s hope that in 60 years, there will be something to stop baldness besides…
March 5th, 2024 by Dr. Hannah Sivak
Why do we use so many plant extracts in our products? Because plants, to survive in difficult environments and fight bacteria, fungi and viruses, evolved sophisticated chemical reactions capable of making complicated chemicals with very special abilities. And we don’t. Humans are complicated enough, but we can’t make stuff like apocynin, beta-glucans, or azelaic acid. For example: if you plant sunflowers in your garden they will do a good job suppressing weeds. How? They produce a chemical called sesquiterpene lactones. These chemicals are a rich source of drugs (some have cytotoxic, anti-tumorgenic, anti-bacterial and anti-fungal properties). They can be toxic to grazing livestock, causing severe neurological problems in horses. Some…
February 29th, 2024 by Dr. Hannah Sivak
Why synergy? “Synergy is an interaction or cooperation giving rise to a whole greater than the simple sum of its parts.” The term synergy comes from the Attic Greek word συνεργία synergia from synergos, συνεργός, meaning “working together.” Most advertising for skincare products tells you about a (secret, new, magical) ingredient that will make all the difference. This is, scientifically speaking, rubbish! Let me explain. Suppose we are discussing one of the ingredients that approximate most a “miracle,” epidermal growth factor. Thousands of scientific articles describe many more experiments documenting how EGF influences the skin. Yet, EGF will do nothing unless the cell it influences has the wherewithal to follow…