Striae distensae is the medical term for stretch marks, those linear, band-like scars that form in the skin when it stretches or shrinks rapidly. They’re one of the most common skin concerns: between 50% and 90% of pregnant women develop them, 6% to 86% of adolescents get them during puberty, and about 43% of people with obesity have them. Despite how widespread they are, no single treatment fully erases them, and no product has been proven to prevent them.
What Happens Inside the Skin
Stretch marks aren’t just surface-level. The damage occurs in the dermis, the thick middle layer of skin that gives it structure and elasticity. When the skin is forced to stretch faster than it can adapt, the connective tissue framework breaks down. Specifically, the fibers responsible for skin’s strength (collagen) and snap-back quality (elastin) undergo damage. Elastin fibers break apart, mast cells (immune cells in the skin) release their contents, and collagen bundles thin out and reorient. The genes responsible for producing collagen and another structural protein called fibronectin may also become less active in affected tissue.
The result is essentially a scar that forms from the inside out. Unlike a cut that heals over a wound, striae form because the internal scaffolding of the skin ruptures under stress. Over time, the remaining collagen can become rigid and cross-linked, making the tissue stiff rather than flexible. This is why stretch marks feel different from the surrounding skin, often slightly indented or textured.
The Two Stages: Red and White
Stretch marks go through two distinct phases. Early stretch marks, called striae rubrae, appear red, pink, or purple. They may feel slightly raised and can be itchy. This redness comes from inflammation and increased blood flow in the damaged area. At this stage, the skin is still actively changing, which is why most treatments work better when started early.
Over months to years, they transition into striae albae: pale, white, or silvery marks that are often slightly depressed below the skin surface. By this point, the collagen bundles have fully thinned and reorganized, the inflammation has resolved, and the blood vessels have retreated. The marks are essentially mature scars. They won’t disappear on their own, though they typically become less noticeable with time.
Common Causes
Two forces drive stretch mark formation: mechanical stretching and hormonal changes. In most cases, both are at play simultaneously.
- Pregnancy is the most recognized trigger. The combination of rapid abdominal expansion and hormonal shifts makes stretch marks almost universal in pregnant women. Younger mothers are at significantly higher risk, with one study finding women 20 or younger had 28 times the odds of developing pregnancy-related stretch marks compared to older women.
- Puberty causes rapid growth spurts that outpace the skin’s ability to adapt, particularly over the hips, thighs, breasts, and lower back.
- Weight fluctuations in either direction can cause them. Rapid weight gain stretches the skin mechanically, but rapid weight loss can also reveal or worsen existing damage.
- Muscle building is a common cause in bodybuilders and athletes whose muscles grow quickly, especially around the shoulders, upper arms, and thighs.
- Corticosteroid use is a major but often overlooked cause. Both topical creams (applied to the skin for conditions like eczema) and oral steroids taken over long periods can thin the dermis and weaken its connective tissue, making stretch marks more likely even without significant stretching.
When Stretch Marks Signal Something Else
Most stretch marks are harmless and tied to an obvious life event like pregnancy, growth, or weight change. But in some cases, they point to an underlying condition. Cushing syndrome, a disorder in which the body produces too much cortisol, causes distinctive wide, purple stretch marks, often on the abdomen, and is accompanied by other signs like weight gain in the face and trunk, easy bruising, and muscle weakness.
Genetic connective tissue disorders like Marfan syndrome and Ehlers-Danlos syndrome also predispose people to stretch marks. In these conditions, the structural proteins in the skin are inherently weaker, so even normal growth or minor stretching can cause significant striae. If stretch marks appear without an obvious cause, or if they’re unusually widespread or severe, it’s worth investigating whether an underlying condition is involved.
Can You Prevent Them?
The short answer: no product has been reliably proven to work. A Cochrane review, the gold standard for evaluating medical evidence, examined multiple topical preparations marketed for preventing stretch marks during pregnancy. The products tested included formulations containing vitamin E, hyaluronic acid, olive oil, and cocoa butter. None showed a statistically significant difference compared to placebo or no treatment. The review concluded that it is not possible to recommend any of the preparations for prevention based on current evidence.
This doesn’t mean moisturizing is useless for skin health generally, but it does mean that the specific claims made by “anti-stretch-mark” creams and oils are not supported by rigorous research. Genetics, skin type, and hormonal factors play a much larger role in determining who develops stretch marks than any topical product.
Treatment Options
Treatments work best on early, red-stage stretch marks and become less effective once marks have matured to the white stage. Nothing completely eliminates them, but several approaches can reduce their appearance.
Topical Treatments
Tretinoin, a prescription-strength vitamin A derivative, is the most studied topical treatment. It can improve the appearance of newer stretch marks by stimulating collagen production, but it cannot be used during pregnancy. Glycolic acid, a chemical exfoliant, is also used to promote skin turnover. Products containing Centella asiatica extract have shown some promise in improving skin elasticity, with one study reporting a 60% reduction in the appearance of existing stretch marks. However, the overall body of evidence for topical treatments remains weak, with few well-designed controlled trials backing any specific product.
Laser Therapy
Fractional CO2 laser treatment is one of the more effective options, particularly for mature white stretch marks that don’t respond to topical products. The laser creates tiny columns of controlled damage in the skin, triggering the body’s wound-healing response and stimulating new collagen production. In one study, after 24 weeks, about 58% of patients treated with fractional CO2 laser alone achieved good improvement (51% to 75% reduction in appearance), and roughly 17% achieved excellent results (over 76% improvement). When the laser was combined with platelet-rich plasma injections, excellent results increased to about 33% of patients.
Multiple sessions are typically needed, spaced several weeks apart. Results build gradually over months as new collagen forms. The treatment involves some discomfort, redness, and downtime, though recovery from each session is generally measured in days rather than weeks.
Microneedling
Microneedling uses a device covered in fine needles to create thousands of micro-injuries in the skin, prompting a healing response similar to fractional laser but less intense. It’s often more affordable and involves less downtime. While microneedling is widely used for stretch marks and has shown clinical improvement in practice, the published evidence comparing its effectiveness directly to laser therapy is still limited. Most people need a series of sessions to see meaningful results.
What to Realistically Expect
Stretch marks are permanent changes to the skin’s structure. Treatments can improve their color, texture, and visibility, but rarely make them invisible. Early intervention during the red stage gives you the best chance of meaningful improvement, since the skin is still actively remodeling and responds more readily to treatments that stimulate collagen production. Once marks have been white and settled for years, improvement is still possible but typically more modest and requires more aggressive approaches like laser therapy.
The psychological impact of stretch marks is real, but it’s worth knowing that they are among the most common skin changes humans experience. They occur across all skin types, all body sizes, and all ages from adolescence onward.