Stretch marks are permanent scars that form in the dermis, the thick middle layer of your skin, when the tissue stretches or shrinks faster than it can adapt. They show up as indented streaks that start out red or purple and gradually fade to pale, silvery-white lines. Nearly everyone has at least a few, and while they pose no medical risk, they bother a lot of people. The science behind why they form, who gets them, and what actually helps is more layered than the cosmetics aisle would have you believe.
What Happens Inside the Skin
Your dermis is rich in collagen and elastin, the proteins that give skin its strength and stretch. When skin expands gradually, the body keeps pace by remodeling those fibers. But when the stretching is rapid or excessive, collagen bundles fracture, blood vessels dilate, and an inflammatory response kicks in. The result is a visible streak that starts out raised, red, or purple, a stage dermatologists call striae rubrae. At this point the tissue is inflamed, slightly swollen, and still actively changing.
Over months to years, the inflammation fades. Collagen that was disorganized during the initial tear flattens out, the tiny blood vessels recede, and the streak lightens into a pale, slightly sunken line known as striae albae. Under a microscope, mature stretch marks show thinned-out skin on top and fragmented, flattened collagen below, a pattern closer to scar tissue than normal dermis. That transition from red to white matters for treatment, because the earlier, inflamed stage responds much better to most therapies than the older, settled stage does.
Why Stretch Marks Form
Rapid body changes are the common thread. Pregnancy is the most familiar trigger. A study of pregnancy-related stretch marks found that women who developed them were on average younger and gained more weight during pregnancy than those who didn’t.1PubMed Central. Risk factors for the development of striae gravidarum But pregnancy is far from the only cause. Adolescent growth spurts, rapid muscle gain from weight training, and weight cycling can all produce the same tearing in the dermis. Anywhere the body expands quickly, stretch marks can follow: abdomen, breasts, hips, thighs, upper arms, and even the lower back.
Hormones amplify the risk. Cortisol, in particular, weakens elastic fibers in the skin. People with Cushing’s syndrome, a condition of chronic cortisol excess, frequently develop wide, deep-purple stretch marks as one of the hallmark signs of the disease.2PubMed Central. Skin manifestations of Cushing’s syndrome Long-term use of corticosteroid medications, whether taken orally or applied as strong topical creams, can produce a similar effect by flooding the skin with cortisol-like activity. Even the normal hormonal surges of puberty and pregnancy raise cortisol enough to soften the dermis and make tearing easier.
Who Is Most Likely to Get Them
Genetics play a bigger role than most people realize. If your mother got stretch marks during pregnancy, your own odds are substantially higher. A large study examining risk factors found that family history was among the strongest predictors, alongside younger age, higher pre-pregnancy body mass index, greater weight gain during pregnancy, and certain skin types on the Fitzpatrick scale.3Journal of the American Academy of Dermatology. Incidence and risk factors for striae gravidarum Women under 20 had dramatically higher odds compared with women over 30, likely because younger skin, though more elastic in some ways, is undergoing rapid hormonal change that makes collagen more vulnerable.
A 2025 cohort study in a Chinese population confirmed these patterns and added that a personal history of stretch marks during adolescence was itself a strong predictor of developing pregnancy-related marks later on.4PubMed Central. Striae gravidarum in the Han Chinese pregnant population: identifying genetic markers and risk factors through a prospective cohort study In other words, if you got them during a growth spurt at age 14, you’re more likely to see new ones during pregnancy or rapid weight change. The genetic component isn’t fully mapped yet, but it’s clear that some people’s skin is structurally more prone to dermal tearing regardless of how carefully they manage their weight.
Skin tone also matters, though in a complicated way. Research has found elevated risk at both ends of the Fitzpatrick scale: very fair skin (type I) and medium-to-olive skin (type IV) showed higher odds compared with an intermediate reference group.3Journal of the American Academy of Dermatology. Incidence and risk factors for striae gravidarum This doesn’t mean darker or lighter skin is “worse,” just that the underlying collagen and melanin composition interacts with stretch in ways researchers are still trying to untangle.
The Cocoa Butter Myth and Other Prevention Claims
Walk through the skincare section of any pharmacy and you’ll find creams marketed specifically for preventing stretch marks, most of them leaning heavily on cocoa butter, shea butter, or olive oil. The evidence for these products is genuinely poor. A Cochrane systematic review, the gold standard for evaluating whether treatments work, found no high-quality evidence to support any topical preparation for preventing stretch marks in pregnancy.5PubMed Central. Topical preparations for preventing stretch marks in pregnancy Cocoa butter and olive oil specifically showed no benefit over doing nothing at all in the studies that tested them.6PubMed Central. Topical management of striae distensae (stretch marks): prevention and therapy of striae rubrae and albae
There is one narrow exception. An earlier Cochrane review noted that a cream containing Centella asiatica extract along with vitamin E and collagen-elastin hydrolysates was associated with fewer women developing stretch marks, but only among women who had already had stretch marks in a previous pregnancy. There was no evidence of benefit for first-time use in the general population.7PubMed. Creams for preventing stretch marks in pregnancy That’s a very specific subgroup, and the overall conclusion stands: no cream has been shown to reliably prevent stretch marks across the board.
Hyaluronic acid has also been explored as a preventive agent, but the evidence remains sparse and inconclusive.8Archiv EuroMedica. Efficacy of Topical Therapies in Treating Stretch Marks: An Evidence-Based Review – Section: Hyaluronic acid preparations This doesn’t mean moisturizing is useless during pregnancy. Keeping skin hydrated can help with itching and comfort. But buying an expensive “stretch mark prevention” cream is, based on current evidence, paying for marketing rather than results.
Treatments That Have Real Evidence
If prevention is mostly a dead end, what about treating stretch marks once they’ve appeared? Here the picture is more encouraging, especially if you catch them early.
Tretinoin for Early Marks
Tretinoin, a prescription retinoid derived from vitamin A, is the best-studied topical treatment. In a controlled trial, about 80 percent of people who applied tretinoin to early, red stretch marks saw definite or marked improvement after six months, compared with fewer than one in ten in the placebo group. The treated marks actually shrank in length and width, while the untreated ones continued to grow.9PubMed. Topical tretinoin (retinoic acid) improves early stretch marks Tretinoin works by speeding up skin cell turnover and stimulating collagen production, but it only seems to help when the marks are still in the inflamed, reddish stage. Once they’ve faded to white, the window for topical retinoids mostly closes. Tretinoin is also not safe during pregnancy or breastfeeding, which limits its use precisely when many people first develop stretch marks.
Microneedling
Microneedling uses a device covered in tiny needles to create controlled micro-injuries in the skin, prompting the body to rebuild collagen in the damaged area. A study following patients long-term found that all treated stretch marks improved by at least 50 percent after an average of fewer than two sessions, and about a quarter of patients saw more than 75 percent clinical improvement. Side effects were limited to temporary redness, with no infections or pigmentation problems across all skin tones tested.10Dermatologic Surgery. Microneedling Treatment of Striae Distensae in Light and Dark Skin With Long-Term Follow-Up That safety profile across different skin types is significant, because many laser-based treatments carry a risk of leaving dark or light patches on melanin-rich skin.
Radiofrequency Microneedling
A newer variation combines microneedling with radiofrequency energy, which heats the deeper layers of skin during the needling process. This combination drives even more collagen remodeling. A comprehensive review found that radiofrequency microneedling is effective and safe for repeated use, including in people with darker skin, and that the collagen rebuilding it triggers continues to improve for at least six months after treatment.11Dermatologic Surgery. Radiofrequency Microneedling: A Comprehensive and Critical Review The “slow and progressive” nature of the results means you won’t see much change right away, but the payoff builds over time.
Laser Therapy
Various laser types have been used on stretch marks, including pulsed dye lasers for red marks and fractional lasers for white ones. Pulsed dye lasers target the blood vessels that make early stretch marks red, reducing the color and sometimes the texture. Fractional lasers create microscopic columns of damage in the skin, triggering a wound-healing response that lays down fresh collagen. Both approaches improve the appearance of stretch marks, though complete elimination is rare.12PubMed Central. Management of stretch marks (with a focus on striae rubrae) Results vary by skin tone, with higher-energy lasers carrying more risk of pigmentation changes in darker skin.
Chemical Peels and Microdermabrasion
Chemical peels use acids to remove the outer layers of skin, encouraging new skin growth and increased collagen production. They can help smooth the texture of stretch marks, but in people with darker skin, peels carry a real risk of causing uneven pigmentation.13PubMed Central. Advancements in treating stretch marks across all skin types: a comprehensive review of therapeutic modalities Microdermabrasion, which physically buffs the skin surface with fine crystals or a diamond tip, is a gentler option that has been widely used for cosmetic improvement of stretch marks and scars.14PubMed. Microdermabrasion Neither method penetrates deep enough to fully remodel the dermis, so they tend to produce modest improvements rather than dramatic ones.
Timing Matters More Than the Treatment You Choose
A thread running through nearly all the treatment literature is that early intervention gets better results. Red or purple stretch marks are still biologically active: the tissue is inflamed, blood supply is increased, and the collagen is still being reorganized. Treatments delivered at this stage are working with a wound that hasn’t finished forming yet, so there’s more to influence. White, mature stretch marks have settled into their final architecture. You can still improve them, but the ceiling is lower and the process is slower.
This creates an awkward practical problem. The period when stretch marks are most treatable, during pregnancy, adolescence, or rapid weight gain, is often a time when people are focused on other things, can’t use certain treatments like tretinoin, or aren’t yet bothered enough to seek help. By the time someone visits a dermatologist, the marks are often years old and already pale. The treatments still help, just not as dramatically as they might have earlier.
Platelet-Rich Plasma and Other Emerging Options
One of the more promising newer therapies is platelet-rich plasma, or PRP. It’s made by drawing your own blood, concentrating the platelets and growth factors, and injecting or microneedling the preparation into the stretch-marked skin. A systematic review found that multiple PRP treatments increased the thickness of the outer skin layer, triggered new collagen and elastin formation, and reduced the inflammatory cell presence in stretch marks.15PubMed Central. Platelet‐rich plasma for striae distensae: What do we know about processed autologous blood contents for treating skin stretchmarks?—A systematic review Another study showed that PRP promoted the remodeling of both collagen and elastic fibers, along with an increase in growth factors associated with tissue repair.16PubMed. Evaluation of the tissue repair process and immunomodulatory action of Platelet-Rich Plasma (PRP) in the treatment of abdominal stretch marks
A particularly interesting recent study compared PRP, nanofat (a processed form of a person’s own fat tissue), and a combination of both. The combined PRP-plus-nanofat treatment produced the greatest increase in collagen production and the best clinical improvement.17PubMed. Effects of Nanofat and PRP on Type I Collagen Production in Striae Distensae: Preliminary Findings from a Prospective, Randomized Single-Blind Study These are still early-stage findings from small studies, so it’s too soon to call PRP a proven solution. But the biological rationale is solid: if the core problem is damaged collagen architecture, flooding the area with concentrated growth factors that drive collagen synthesis makes sense as an approach.
The Emotional Weight of Stretch Marks
Stretch marks are sometimes dismissed as a purely cosmetic nuisance, but the psychological impact can be real and substantial. A study of pregnant women found that over a third reported moderate to significant embarrassment and self-consciousness related to their stretch marks. The severity of the marks correlated with how much they affected overall quality of life, clothing choices, self-esteem, anxiety, and willingness to participate in social activities.18PubMed Central. Negative perceptions and emotional impact of striae gravidarum among pregnant women Almost a quarter of participants felt that the emotional distress from stretch marks was as bad as or worse than what they’d expect from conditions like acne, psoriasis, or eczema.18PubMed Central. Negative perceptions and emotional impact of striae gravidarum among pregnant women
This matters because doctors and the people around someone with stretch marks sometimes minimize the concern. “They’re just stretch marks” is a common refrain, but for someone avoiding the pool or feeling distressed getting dressed in the morning, the experience is anything but trivial. Validated assessment tools now exist specifically to measure stretch-mark-related distress, a recognition by the medical community that these marks warrant attention as more than a vanity issue.19Aesthetic Surgery Journal. The BODY-Q Stretch Marks Scale: A Development and Validation Study
Why Treatment Choices Depend on Your Skin Tone
One of the least-discussed aspects of stretch mark treatment is how much your skin tone influences what’s safe and effective. Many energy-based treatments, including certain lasers and chemical peels, work by creating controlled damage that triggers repair. In lighter skin, the risk of pigmentation changes from that damage is relatively low. In darker skin, the same treatment can leave patches that are darker or lighter than the surrounding area, sometimes for months or permanently.
Microneedling stands out as one of the safer options across the skin-tone spectrum, with studies showing no pigmentation problems even in darker phototypes.10Dermatologic Surgery. Microneedling Treatment of Striae Distensae in Light and Dark Skin With Long-Term Follow-Up Radiofrequency microneedling shares that advantage.11Dermatologic Surgery. Radiofrequency Microneedling: A Comprehensive and Critical Review Chemical peels, by contrast, require careful selection and lower concentrations in darker skin to avoid making things worse.13PubMed Central. Advancements in treating stretch marks across all skin types: a comprehensive review of therapeutic modalities If you have medium to dark skin and are considering treatment, this is worth raising with your provider before any procedure. The treatment that works beautifully on a fair-skinned patient in a before-and-after photo might not be the right choice for you.
Stretch Marks in Bodybuilding and Rapid Muscle Gain
Pregnancy and puberty dominate the conversation about stretch marks, but anyone who has spent time in a gym has probably noticed them on the shoulders, upper arms, and chests of people who put on muscle quickly. Rapid muscle growth stretches the overlying skin in the same way a growing belly does, and if the growth outpaces the skin’s ability to remodel its collagen, tears form. Anabolic steroid use amplifies the problem further, both by accelerating muscle gain and by disrupting the hormonal balance that maintains skin elasticity, much like the cortisol mechanism seen in Cushing’s syndrome.
Among bodybuilders and athletes, these marks are sometimes treated as a badge of effort, but plenty of people find them distressing. The same treatments that work for pregnancy-related marks apply here, and the same principle holds: catching them while they’re still red gives you the best shot at improvement. If you’re putting on muscle rapidly, there’s no proven way to prevent the marks from forming, but managing the pace of weight gain, when possible, at least reduces how severe they get.