Stretch marks are a type of scar that forms when skin stretches or shrinks faster than its underlying structure can keep up with. The rapid change causes collagen and elastin, the two proteins responsible for skin’s strength and elasticity, to rupture. As the skin heals over those broken fibers, visible lines appear on the surface. They affect 50 to 90% of women at some point in life and are extremely common during adolescence for both sexes.
What Happens Inside the Skin
Your skin has two main layers: a thin outer layer (epidermis) and a thicker structural layer beneath it (dermis). The dermis contains networks of collagen and elastic fibers that let skin stretch and snap back. When the body grows or changes shape quickly, those fibers can’t remodel fast enough. They break apart, and the elastic fibers retract and curl at the edges of the tear, forming tangled clusters visible under a microscope.
In the earliest stage, the area becomes mildly inflamed. Immune cells flood the dermis, and swelling sets in around small blood vessels. This is why fresh stretch marks often look raised and feel slightly different in texture compared to surrounding skin. Over time, the outer skin layer flattens and thins, and the broken collagen reorganizes into dense, horizontal bundles, essentially forming scar tissue. The result is a permanent change in skin architecture, though the marks do become far less noticeable with time.
How Stretch Marks Change Over Time
Fresh stretch marks, sometimes called striae rubra, start out as raised lines that are red, purple, or violet depending on your skin tone. They may feel slightly itchy or tender. This early stage involves active inflammation and ongoing tissue remodeling, which is also the window when treatments tend to be most effective.
Over months to years, the color fades and the texture shifts. The marks flatten, become wrinkled, and turn lighter than your surrounding skin. In people with lighter complexions, they settle into a pale, silvery white. In darker skin tones, healed stretch marks can appear darker (sometimes described as blue-gray or deep brown) due to differences in how pigment behaves in scarred tissue. At this mature stage, the skin in those areas has significantly less elastin and a protein called fibrillin compared to normal skin nearby.
Common Causes and Risk Factors
Any situation that forces skin to expand or contract rapidly can trigger stretch marks. The most common scenarios include:
- Pregnancy. The abdomen, breasts, and hips expand significantly over a short period, making stretch marks nearly universal among pregnant women.
- Puberty. Growth spurts cause rapid stretching across the thighs, hips, buttocks, and back. Reported prevalence in adolescents ranges widely, from 6 to 86%, depending on the population studied.
- Rapid weight gain or loss. Whether from lifestyle changes, bodybuilding, or medical conditions, quick fluctuations in body size strain the dermis.
- Corticosteroid use. Steroid creams, pills, or injections used for conditions like asthma, lupus, or rheumatoid arthritis can thin the skin and weaken collagen if used in large amounts over long periods. This makes the skin more vulnerable to tearing even with mild stretching.
- Cushing syndrome. This condition causes the body to produce too much cortisol, a natural steroid hormone. One of its hallmark signs is wide, pink or purple stretch marks, particularly on the abdomen and upper arms.
Genetics also play a significant role. If your parents developed stretch marks, you’re more likely to get them. This likely relates to inherited differences in skin elasticity and collagen structure, though the exact genetic pathways aren’t fully mapped out. You can do everything “right” and still develop them if your biology leans that way.
Do Prevention Creams Actually Work?
Cocoa butter is probably the most popular product marketed for stretch mark prevention, especially during pregnancy. A randomized, placebo-controlled trial published in the New England Journal of Medicine put this to the test: 210 first-time pregnant women applied either a cocoa butter and vitamin E lotion or a placebo lotion daily starting at 12 weeks. The result was no measurable difference between the two groups. Cocoa butter did not prevent stretch marks.
This pattern holds for most over-the-counter oils and creams. While keeping skin moisturized can reduce itchiness and improve comfort during stretching, there is no strong clinical evidence that any topical product prevents stretch marks from forming. The process happens deep in the dermis, well below where most moisturizers penetrate.
Treatments That Can Help
No treatment completely erases stretch marks, but several options can make them significantly less visible, especially when started early.
Retinoid Creams
Prescription retinoid creams (derived from vitamin A) can improve the appearance of stretch marks that are less than a few months old. They work by stimulating the skin to rebuild collagen, helping the scarred area look more like normal surrounding skin. These creams are not safe to use during pregnancy or breastfeeding.
Microneedling
This procedure uses tiny needles to create controlled micro-injuries in the skin, triggering the body’s natural healing response. It physically disrupts the dense, abnormal collagen in the scar and encourages it to remodel into a more organized pattern. Most studies show visible improvement after 2 to 4 sessions, with continued gains for up to 6 months after the final treatment. Sessions are typically spaced about a month apart. For microneedling to work well on stretch marks, the marks generally need to be at least one year old, meaning the skin has fully stabilized.
Laser Therapy
Fractional laser treatments target the deeper skin layers to stimulate new collagen production. Like microneedling, these require multiple sessions and work best as part of a sustained treatment plan. Results vary by skin tone and stretch mark severity. Neither laser nor microneedling will make stretch marks disappear entirely, but both can reduce their width, depth, and color contrast enough that they become much harder to notice.
What Determines How Yours Will Look
Several factors influence how prominent your stretch marks are and how well they respond to time or treatment. Skin tone matters: marks tend to be more visually striking on darker skin, where pigment changes add contrast. Location also plays a role, since areas with thinner skin or more tension (like the lower abdomen and inner thighs) often develop deeper marks. How quickly the stretching happened matters too. Gradual weight gain gives collagen more time to adapt, while sudden changes (a growth spurt, rapid muscle gain, or a twin pregnancy) create more severe tearing.
Age is another variable. Younger skin tends to be more elastic and may recover better, though younger people are also more prone to developing stretch marks in the first place because of how rapidly their bodies change during puberty and early adulthood. Over years, even untreated stretch marks typically fade substantially and become less textured, blending more naturally into the surrounding skin.