Reference Lab

APRIL 20, 2022

Where do dead skin cells go? That’s not an existential question. If you’re interested in keeping your skin looking healthy and fresh, then understanding what happens to dead skin cells is essential.

Our skin is the largest organ of the body and it serves as its shield, protecting the body from physical injury, chemical and biological dangers, and UV radiation. And because the skin is subject to the onslaughts of daily life, it must renew itself to do its job effectively. The epidermis, the skin’s outermost layer, continually restores itself. This layer constantly sheds dead skin cells and allows new, fresh cells from below to take their place. As you age, however, your skin needs your help to renew itself efficiently. The life story of epidermis skin cells is a short and heroic one, with skin cells protecting the body every step of the way. On average, your skin sees a new outer layer of cells every 28 days. The most abundant type of skin cells are keratinocytes, which make up about 90-95% of all cells in the epidermis.^1,2 Keratinocytes produce keratin, a protein that acts as a sturdy and waterproof defense against the environment. These cells start from stem cells in the lowest layer of the epidermis. In this layer, called the basal layer, skin cells are fed a nutrient-rich blood supply. As even newer cells develop, these cells get pushed up toward the upper layers, further away from its source of nutrients. As the cells move upwards they develop more and more keratin, becoming harder, flatter, and dryer. By the time they’ve reached the stratum granulosum, the cells develop a more granular appearance and are highly keratinized. It’s also at this point that they begin their cellular death. As the cells enter the stratum lucidum — the second to the uppermost outer layer — they have flattened and died, because of their increasing distance from the nutrient-rich blood supply of the basal layer. ^1,2 When skin cells have reached the stratum corneum, they have all died — having spent their life protecting the cells below. The stratum corneum is made of about 20 layers of dead skin cells, called corneocytes, that are eventually shed.^1,2 Epidermal keratinocytes experience a programmed cell death with a funny name – cornification. Cornification turns dead skin cells into a keratin-rich barrier for the skin, called the cornified layer. The cornified layer is the outermost skin barrier, and it’s what you see when you look at your skin. So, in short, the topmost layer of your skin is made of dead cornified skin cells. But before you look at your skin in horror at this thought, know that a few layers of dead skin cells are necessary to protect the younger skin cells beneath. ³ Your cornified dead skin cells don’t remain on your skin forever. The topmost layer of dead skin cells typically slough off naturally, either when you bathe or as you move throughout your day (or night), in a constant state of renewal. As you age, however, two factors affect the amount of dead skin cells on face and body. First, your body begins to accumulate more dead skin cells the older you get. Secondly, the natural processes that allow dead cells to slough off easily decline. Therefore, dead skin cells accumulate with age and result in dull, uneven, and more flaky skin the older you are. ³ How dead skin cells affect skin health depends on how much dead skin accumulates. Dead skin cells play an important role when it comes to the skin’s barrier, keeping moisture in and foreign particles out. If you slough off too much of your dead skin cells by using a harsh exfoliant, for example, you might compromise your skin’s barrier function and find yourself with sensitive, dry skin. ( 01) An adequate layer of dead skin cells is necessary to protect the newer skin below. On the other hand, too many layers of dead cells can harm your skin and contribute to dull, oily, and sensitive skin. Besides natural cell death, skin cells also experience aging through a process called cell senescence – a process which marks the halt of cell replication and the transition from being a normal cell to a senescent one. If the body doesn’t clear away senescent cells and they are left to linger in the skin, they emit inflammatory signals which cause the cells around them to enter into senescence as well. Too many dead skin cells and senescent cells encourage more skin cells to die, therefore reducing the amount of healthy, functional cells that can deliver glowing skin from the inside out. Healthy skin is about balance. Your skin needs some dead skin cells, but not too many. An overly-thick layer of dead skin, however, harbors oil and bacteria, leading to acne breakouts, infections, or dry, flaky skin. Here are a few factors that lead to a buildup of dead skin cells.

• Cleaning Routine: Prior to applying topical skin care products, cleansing your skin regularly helps slough off loose dead skin cells. Skip bathing or washing your face for a week and you’ll probably see irritations and oiliness that can ultimately impact skin’s condition.
• Age: Cell turnover slows as you age. In fact, a child’s cell turnover rate is double that of someone in their late adulthood, which is why dead skin cells become a problem later in life. ⁴
• Sun Exposure: Sunshine injures skin cells, speeds up skin cell death, and contributes to increased levels of senescence. Over time, sun damage can result in an accumulation of dead skin cells and destruction of lower layers of skin, causing sagging and age spots.

These three factors are the most common culprits for dead skin cell buildup, but other issues like genetics, skin conditions, medications, and health problems also play a part. When dead skin cell buildup occurs, the skin on the face and body appears uneven, sallow, and dull. Furthermore, an over-accumulation of dead skin cells affects the skin’s oil production and hydration, making the skin simultaneously oily and dry! So, you can’t bring dead skin cells back to life, but you can do a few things to preserve your healthy, young cells and repair cells that have been damaged but aren’t dead yet.

1. Exfoliation: Removing dead skin cells through light and gentle exfoliation will help unveil a new layer of healthier, younger cells. Just be sure not to exfoliate too much, as this could compromise your skin barrier, resulting in uneven skin texture or tone. ⁵
2. Remove senescent cells: If you have wondered how to get rid of senescent cells naturally, it is possible. Doing so will eliminate the contaminating culprits that coax other skin cells into senescence, effectively preventing unnecessary early cell death and extending your skinspan. This requires a special class of molecule, called “senotherapeutics”, which selectively target senescent cells. OneSkin’s line of Topical Supplements are powered by a senotherapeutic peptide, called OS-01, which reduces cellular senescence in skin by up to 50%. By targeting cellular senescence, the OS-01 peptide has been scientifically proven to reduce skin’s biological age, effectively extending your skinspan. OneSkin is the first company to target cellular senescence as a way to promote skin health and extend skinspan.
3. Repair (live) skin cells: While you can’t resurrect a dead skin cell, you can utilize ingredients that help repair damage to live skin cells. In fact, not only does OneSkin’s OS-01 peptide reduce cellular senescence in skin, it also aids in repairing sun damaged skin to keep skin cells healthier for longer. Other ingredients that have been shown to aid in cellular repair include specific antioxidants for skin, which reduce free radicals, helping to prevent DNA damage.

The skin on your face and your body needs your help to remove dead skin cells, especially as you age. However, scrubbing off all your dead skin is unsafe because you need them as a barrier. But too many dead skin cells leads to unhealthy, dull skin. So, how can you effectively remove dead skin cells from your face and body? By exfoliating in moderation and using the right products that won’t aggravate or impact current skin condition. According to the American Academy of Dermatology Association, exfoliating resurfaces your skin and is an excellent technique for removing dead skin cells—but it needs to be done in moderation and followed up with moisturizing products that use nourishing ingredients, whether it be a rejuvenating lotion specifically formulated for the face or ultra-hydrating body lotion with peptides. ⁶ Mechanical exfoliation removes dead skin cells through the action of something repeatedly brushing against the skin. Using a washcloth, body scrub, cleansing brush, or pumice stone physically removes dead skin while cleaning wet skin. Another way to exfoliate dead skin cells on the body is through dry brushing. In dry brushing, a large soft brush repeatedly runs over the skin, encouraging dead skin cells to slough off. Unlike mechanical exfoliation, chemical exfoliation doesn’t use any tools or scrubs. Chemical exfoliation uses skin-safe chemicals to dissolve dead skin cells. These chemical exfoliants dissolve dead skin without the abrasiveness and tissue injury that can accompany mechanical exfoliation. ^6,7

• The epidermis constantly renews its cells from the bottom up, with fresh cells on the bottom and dead skin cells at the very top.
• Dead skin cells help serve as part of the skin barrier, but too many dead skin cells can affect skin tone and texture, leading to a rough and dull appearance. A surplus of dead skin cells and the presence of senescent cells can accelerate skin aging.
• Your skin needs help removing excess dead skin cells, through gentle exfoliation, and removing senescent cells with products like OneSkin’s Topical Supplements.

1. https://www.ncbi.nlm.nih.gov/books/NBK26865/
2. https://www.ncbi.nlm.nih.gov/books/NBK470464/
3. https://onlinelibrary.wiley.com/doi/abs/10.1002/9780470015902.a0021583.pub2
4. https://onlinelibrary.wiley.com/doi/10.1111/j.1468-2494.2010.00611.x
5. https://pubmed.ncbi.nlm.nih.gov/9732048/
6. https://www.aad.org/public/everyday-care/skin-care-secrets/routine/safely-exfoliate-at-home
7. https://www.sciencedirect.com/topics/materials-science/hyaluronic-acid