Browse evidence-based analysis of health-related claims and assertions
In half of adult women with acne, high male hormone levels or extra-sensitive skin receptors are to blame — and in most of those cases, it’s linked to PCOS, a hormonal disorder.
Descriptive
About 1 in 5 adult women still get acne after age 25, and it’s different from teenage acne.
Quantitative
In adult women, acne happens because the skin makes too much oily stuff, which clogs pores and lets bad bacteria grow, causing red bumps and scars.
Mechanistic
If you block the ATM protein in skin, the skin tans more after sun exposure because it can’t pause pigment production to fix DNA damage.
After sun exposure, a chemical tag (phosphate) is added to a protein called MITF, making it stop making pigment and instead team up with other proteins to fix DNA damage.
After you get sunburned, your skin temporarily stops making tan pigment because a protein called ATM redirects another protein (MITF) to fix DNA damage instead of making color.
When exposed to UV light in the lab, this sunscreen didn't make human skin cells become toxic or die, meaning it doesn't cause harmful reactions when hit by sunlight.
This sunscreen uses special fat-based nanoparticles and a plant-derived compound to help the sunscreen stay stable and not get absorbed into the body.
After 8 hours, about 28% of one UV filter and 40% of another slowly leaked out of the sunscreen, meaning it releases the active ingredients slowly over time.
This sunscreen stayed effective even after being exposed to strong UV light — equivalent to 10 times the amount that would normally cause sunburn — without breaking down.
When tested on human skin cells and skin models, this sunscreen didn't kill cells or cause irritation, so it might be gentle on skin.
How often you get Botox or how young you start doesn’t change how your face ages naturally — your skin follows the same aging path no matter what.
Botox doesn’t stop your face from drooping as you get older — everyone’s face sags the same amount over time, no matter how often you get injections.
Botox doesn’t stop your skin from losing collagen as you age — everyone loses it at the same rate, no matter how often you get injections.
No matter when or how often you get Botox, your skin keeps getting thinner over time, and Botox doesn’t slow that down.
Botox injections make wrinkles look better for the first few years, but after 15 years, everyone’s wrinkles look about the same no matter how often or how young they started getting injections.
Older people tend to get more Botox injections than younger people when treating frown lines.
Correlational
On average, people get about 7 units of Botox between their eyebrows and about 4 units in the forehead line above the nose, and men and women get roughly the same amount.
People with stronger forehead muscles and deeper wrinkles between the eyebrows tend to get more Botox injections than those with weaker muscles and lighter wrinkles.
Cellulite is caused by fibrous septae tethering the dermis to underlying fascia, creating dimpling as subcutaneous fat herniates through these structures; enzymatic disruption of these septae can reduce the appearance of cellulite.
Assertion
Oral collagen supplementation does not significantly increase dermal collagen synthesis or reduce skin wrinkling in humans, as ingested collagen peptides are metabolized into amino acids and do not selectively target skin tissue.
Repeated facial muscle contractions induce dynamic wrinkles that, over time, become fixed static lines due to collagen and elastin degradation; neuromodulators such as botulinum toxin prevent this progression by inhibiting neuromuscular transmission.
Topical and systemic minoxidil stimulates hair follicle growth in a dose-dependent manner by enhancing dermal blood flow and nutrient delivery, regardless of the underlying cause of hair loss, and its mechanism of action is independent of androgen pathways.
The concept of comedogenicity as applied to modern topical skincare products is largely invalid; the vast majority of commercially available oils and emollients, including petrolatum and olive oil, do not induce follicular occlusion or acne formation in human skin.