Yes, stretch marks are completely normal. They’re one of the most common skin changes humans experience, showing up in roughly 80% of people at some point in life. About 70% of adolescent girls and 40% of adolescent boys develop them during puberty alone, and between 50% and 90% of pregnant women get them. If you have stretch marks, you’re firmly in the majority.
Why Stretch Marks Form
Stretch marks happen when your skin stretches faster than it can adapt. The middle layer of your skin contains a network of fibers that give it elasticity and structure. When that layer gets stretched too quickly, immune cells in the skin release enzymes that break down those elastic fibers. The result is a visible scar where the skin’s internal scaffolding has been reorganized.
The hormone cortisol plays a role too. Cortisol, which your body produces naturally during stress, puberty, and pregnancy, weakens the elastic fibers in your skin and makes them more vulnerable to tearing when stretched. That’s why stretch marks tend to cluster around life stages when both rapid body changes and hormonal shifts happen at the same time.
When They Typically Appear
Puberty is the single most common trigger. A study of Korean students aged 15 to 17 found stretch marks in 83% of them, with boys slightly more affected (88%) than girls (77%) in that group. In adolescent girls, they most often show up on the thighs, buttocks, and breasts. In boys, the lower back is the most common site, since that area stretches during growth spurts.
Pregnancy is the other major trigger, with estimates ranging from 50% to 90% of pregnant women developing them. They typically appear on the abdomen, breasts, and hips during the second and third trimesters as the skin stretches to accommodate the growing baby.
Rapid weight gain or loss at any age can cause them. So can building muscle quickly. Bodybuilders and people who weight train intensely sometimes develop stretch marks on their biceps, shoulders, or chest when muscle growth outpaces the skin’s ability to stretch.
Genetics Matter More Than You Think
Whether you get stretch marks, and how severe they are, is strongly influenced by your genes. If your parents have prominent stretch marks, you’re more likely to develop them too. Some people’s skin simply has more natural elasticity than others, and research has identified genetic variations in the proteins that make up elastic microfibers as a factor in who develops them. This is why two people can go through the same pregnancy or the same growth spurt and end up with very different skin.
How They Change Over Time
Fresh stretch marks start out red, pink, or purple. At this stage, they may look raised or feel slightly swollen. The color comes from increased blood flow to the area as your body responds to the damage in the skin’s deeper layers.
Over months to a few years, that color fades. The marks flatten, lose their redness, and gradually turn white or silvery. At this point, they’re essentially depressed, pale scars with a slightly wrinkled texture. They never disappear entirely on their own, but in many people they become faint enough to be barely noticeable.
Do Creams and Oils Actually Work?
Despite the massive market for stretch mark creams, the evidence is discouraging. A Cochrane review, the gold standard for evaluating medical evidence, found no high-quality evidence that any topical preparation prevents stretch marks during pregnancy. Women who used creams with active ingredients developed stretch marks at essentially the same rate as women who used a placebo or nothing at all. The severity of the marks was no different either.
For treating existing marks, over-the-counter creams and oils perform poorly. In one study, nearly 90% of patients tried creams and oils as their first treatment, but reported only about 9% improvement. Prescription-level treatments like chemical peels and retinoids performed somewhat better at around 21% improvement. Laser therapy showed the most benefit at roughly 42% improvement, and it works best on newer, still-red marks rather than older white ones.
The takeaway: moisturizing your skin is fine for comfort, but no cream will reliably prevent or erase stretch marks. If the appearance of your marks bothers you, laser treatments offer the most realistic improvement, particularly if started while the marks are still in their early red or purple phase.
When Stretch Marks Signal Something Else
In rare cases, stretch marks can be a sign of an underlying medical condition. Cushing syndrome, a condition where your body produces too much cortisol, causes stretch marks that look distinctly different from ordinary ones. They tend to be wider (sometimes over a centimeter across), deeper in color, and can appear in unusual locations including the face. They may also appear without any obvious trigger like weight gain, pregnancy, or growth.
Long-term use of corticosteroid medications, whether oral or topical, can cause similar wide, prominent marks. Marfan syndrome, a genetic connective tissue disorder, also makes stretch marks more likely because the skin’s structural fibers are inherently weaker.
Ordinary stretch marks are typically a few millimeters wide, appear in predictable locations tied to growth or weight changes, and fade over time. If your stretch marks are unusually large, appear suddenly without an obvious cause, or show up in uncommon areas, that’s worth mentioning to a doctor to rule out hormonal or connective tissue conditions.