What are stretch marks?
In a nutshell, stretch marks (medically known as ‘striae’) are a type of scar which develops when our skin stretches more rapidly than it is prepared for.
We can get stretch marks almost anywhere on our bodies depending on how, when, and where we grow most quickly.
When your skin is stretched faster than it can accommodate, small tears happen in two of the proteins that make up its structure: elastin and collagen. Elastin’s main role is to allow your skin to stretch. Collagen’s role is to provide structure, strength and support for your skin. Like with scars, the tearing impacts how the protein structures re-grow during healing. This gives the healed skin a different texture and colour, resulting in a mark.
Why stretch marks occur
Your skin is much more complicated than meets the eye. It’s made up of three layers, the epidermis, dermis, and the hypodermis.
Stretch marks form in the middle layer - the dermis - when the connective tissue is stretched beyond the limits of its elasticity, usually due to rapid expansion of the surface of the skin.
This causes the dermis to tear, which shows through all the way to the top layer, or epidermis.
What do stretch marks look like?
There are two main classifications of stretch mark appearances, striae rubrae and striae albae.
Striae rubrae: Red stretch marks
Striae albae: White stretch marks
With time, as they heal, these marks usually become hypopigmented, meaning they’ll fade to a paler shade than the surrounding skin. In people with lighter skin they may eventually settle to silver-white, and in those with darker skin to a peachy-beige. Sometimes they will still feel indented or ridged, but that typically evens out.
Due to everyone having different skin-types and shades, not all stretch marks appear the same. They all usually fade with time without completely disappearing. The transition between striae rubrae and striae albae can take several months to years.
Who gets stretch marks?
Anyone can get them.
Stretch marks during pregnancy
Stretch marks are most common in people who are pregnant as that’s one of the most dramatic, rapid (and impressive!) periods of growth a human body can achieve. Over the course of a pregnancy the uterus expands from the size of a small orange to the size of a large watermelon - and your skin stretches to accommodate this.
Stretch marks during adolescence
Teenagers going through rapid growth spurts frequently get stretch marks, although they’re less likely to notice them at the time. You may even have stretch marks on your body from when you were going through puberty - especially if you were one of those kids who were said to have ‘shot up in their sleep’! If you’re curious, check your hips, the sides of your knees, and sometimes even your elbows for faded silvery lines.
Stretch marks during weight gain
You may also experience stretch marks if you gain a large amount of weight or body mass rapidly e.g., you are a bodybuilder. At least 43% of those suffering from obesity develop stretch marks.
Other stretch mark risk factors
You may get stretch marks if you’re experiencing a hormonal condition that affects the amount of cortisol released by your adrenal gland e.g., the rare condition Cushing syndrome, or if you are using corticosteroids. You can be more likely to develop them if you have Ehlers-Danlos Syndrome or another condition which affects your body’s collagen. You can form stretch marks from surgical procedures involving tissue expanders e.g. breast augmentation or reconstruction, and even from extremely rapid weight loss.
When stretch marks appear in pregnancy
Stretch marks are extremely common in pregnancy, affecting up to 90% of mothers. Typically, they occur in the 6th or 7th month, but they can occur as early as 24 weeks depending on how fast your baby grows.
You may be statistically more likely to get stretch marks if:
- you are female
- you mother and grandmother(s) got them
- you have a darker/more melanated skin tone
- you’re medically overweight
- you’re a younger pregnant person
- you have a baby in a higher weight percentile
Why stretch marks occur?
The simple answer is because when human skin stretches too fast it can tear, and the tear can heal like a scar.
The more detailed answer goes something like this…
In an ideal world, the elastin and collagen in our skin cells would facilitate all the ways our body can grow and change, but the reality is that although our skin is dynamic and has strong self-repair mechanisms, we are constantly exposed to external environmental factors that impair its performance. Combined with the pressures of stretching to accommodate a growing baby, this can create a situation where your skin’s capacity to stretch is more limited, the skin tears and the result is stretch marks.
Other factors in the formation of stretch marks
There are various reasons why the proteins in the cells of the dermis might be more liable to tear under certain conditions. In addition to some medical conditions that might impact how collagen and elastin are produced in the body, there is evidence that your hormones have a role to play. Although we don’t yet fully understand all the mechanics, most of us have experienced the instantly noticeable impact of hormonal changes on our skin. We may prefer to forget about it, but who hasn't experienced spots and greasy skin in their teen years; breakouts linked to your menstrual cycle; or changes to your skin after going on a contraceptive pill. Other big hormonal changes such as pregnancy and menopause also undoubtedly affect how your skin looks and feels. Specifically in the case of stretch marks, if you have high levels of the hormone cortisol your skin is likely to be more fragile, as it weakens elastin fibres. Similarly, excessive unprotected sun exposure can damage collagen in the skin.
Stretch marks can be itchy
This stretching and tension can cause inflammation - the reason why stretch marks appear pink or red at first, and why they may itch in their earliest phases. During this process the dermal layers lose elastin and denser collagen fibres form. This forms the ‘scar tissue’ that makes stretch marks difficult to remove and in most cases, once this has happened, they become permanent. Hence why, although stretch marks do fade, they don’t fully disappear.
Are stretch marks harmful?
Short answer, no. There is no research that suggests stretch marks are any more harmful than any other type of scar.
However, some people don’t like the way stretch marks look on their body and that can cause distress and anxiety. Pregnant people, especially, may already be struggling with the rapidity of changes to their body - especially if it’s your first baby - and these visible and lasting marks may be an additional struggle. Teenagers with body-image anxiety or dysmorphia may also find them difficult - again because they’re a visual reminder that your body’s a bit ‘out of control’ during this phase of your life.
Much of the time, one of the first things we notice about other people is their skin, and we often make all kinds of unconscious (and ultimately unfounded) assumptions about their health and quality of life based on our impression of it. It might be irrational, but we’ve all absorbed all kinds of biases about what healthy skin looks like means that when our own skin undergo changes, or feels like it’s not at its best, it can have a big impact on our self-esteem and confidence. The psychological impact of less than airbrush-perfect skin is often under-appreciated
It’s important to remember that there’s nothing wrong with investing time and attention into feeling at home in your body through self-care: whether that’s skin care, psychological care, or both!
Many people find embracing body positivity - ‘they’re my tiger stripes/they’re a badge of honour’ - or body neutrality ‘they’re just a consequence of my body doing what it’s doing, neither good nor bad’ helpful when coping with the distress that stretch marks can cause. There’s nothing wrong with having stretch marks, and there’s nothing wrong with trying to avoid or get rid of them. A dermatologist can offer you support or guidance, whether you’re hoping to prevent them occurring or looking for ways to remove or reduce them.
How can stretch marks can be removed?
Professional stretch mark treatment
Some dermatologists and cosmetic surgeons might recommend treatments such as
- Microdermabrasion
- Laser and pulsed light therapies
- Microneedling
- Chemical peels
- Radiofrequency devices
There isn’t, however, any industry consensus about whether these are 100% effective. These treatments, used individually or in a combination, can help people in some cases, but there are no guarantees. Treatments like these are also not straightforward or simple, and will involve multiple sessions, significant costs and potential side effects such as irritation, post-inflammatory hyperpigmentation, or dyspigmentation. The results may not be predictable and may require regular ‘top ups..
If you opt for treating your stretch marks with one of these methods, you will need to consult extensively with a good dermatologist or cosmetic surgeon, who could advise you on the viability of the treatment, identifying potential issues or vulnerabilities specific to your skin type and condition. Like stretch marks themselves, procedural treatments will impact everyone’s skin differently.
Overall, the earlier treatments are applied, the better your chances of their making a difference; striae rubrae have shown better responsiveness to both topical and procedural treatment than striae albae.
Are stretch marks permanent?
It’s also important to note that complete removal of stretch marks should not be expected with any of these treatments. At best they can help to improve the colour and texture of the marks to reduce the contrast with the surrounding skin.
Which stretch mark cream is best?
At-home stretch mark treatment
There are plenty of topical preparations billed as ‘stretch-mark solutions’ - just google ‘how to get rid of stretch marks’ and you’ll find them all over the sponsored results. You may even have some marketed to you by your algorithm if you’re pregnant or have just given birth. Despite claims on the labels of various products, very few have been formally trialled in high quality clinical studies.
The most studied topical treatment is a retinoid known as tretinoin (retinoic acid). It may help improve the appearance of stretch marks when applied in the earliest stages of stretch mark formation although the evidence suggests it has limited capabilities when used on more mature stretch marks. Retinoids also have various potential side effects including irritation and inflammation, dryness and scaling, and increased sun sensitivity.
Most importantly, due to their potential to increase the risk of birth defects, retinoids (also known as vitamin A) cannot be safely used by pregnant or breastfeeding people - the population most likely to be affected by stretch marks.
Since the most clinically studied topical product, tretinoin, is not available to pregnant people, many women turn to other over-the-counter treatments claiming to be able to remove stretch marks. However, both the Advertising Standards Authority and the NHS agree that claims about being able to fade stretch marks completely should be classed as lacking sufficient evidence.
The best thing to do with existing stretch marks is to support overall skin health with hydration, moisturisation, and balanced nutrition.
Can you do anything to prevent stretch marks?
While there’s no guarantee that you can completely evade stretch marks, there are some things you can do to support your skin and reduce the likelihood of developing them.
Lifestyle choices to help prevent stretch marks
Firstly, you can support your overall skin health with a balanced diet, regular exercise, good hydration, gentle cleansing, and moisturising your whole body regularly. Wearing SPF in the sun, and avoiding tanning beds, and prolonged use of corticosteroids also help protect the skin’s underlying structures. There are external factors in our modern lifestyle which affect our skin’s ability to do its job perfectly, many of which can be counteracted by topical treatments that support the skin’s natural functions.
Using a retinoid to help prevent stretch marks
If you’re worried about stretch marks developing for reasons other than pregnancy, you could try using a body moisturiser that includes a low dose of a retinol (vitamin A) and hyaluronic acid. This might be a good solution for teens also struggling with body acne. Use of any retinoid should always be followed by application of SPF, as they can increase sensitivity to sun exposure. You should always check any product warnings and directions for use!
Using a natural moisturiser to help prevent stretch marks
For pregnant people, vitamin A products - and most strong and synthetic skincare ingredients - are not an option, and a natural at-home treatment is ideal. Although there isn't much robust data on specific ingredients that can prevent stretch marks during pregnancy, there are plenty of science-backed arguments for moisturising.
Moisturising helps support our skin’s dual function as a barrier; both keeping things out of our body, and keeping things in - most importantly, water!
If your barrier function has been impaired the protective qualities of your skin begin to suffer in the long term. Less than optimal water content results in a decrease in the softness and suppleness of your skin, and an increase in fragility and brittleness.
This surface dehydration is the first step in the development of the dry skin cycle. Most moisturisers (also called emollients) have an occlusive effect as well as a hydrating effect. Occlusive means that they form a semi-permeable protective layer on the skin, which reduces or inhibits trans epidermal water loss (TEWL). Excessive loss of water through your skin has a domino impact on many aspects of your health and on your skin’s appearance.
Water acts as a plasticiser, imparting an elastic property to your skin-cell proteins. When your skin cells are deprived of water, the proteins become more fragile and the skin cracks with mechanical stress.
A balanced moisturising product increases the skin’s water content, simulates and replenishes the role of the skin’s lipids, and restores the normal functioning of the lipid barrier.
Some research indicates that TEWL increases slightly in pregnancy and the postnatal period, which supports the argument that you should be taking additional steps to support your skin at this time. Self-care can have the added benefit of being a moment to take back a little time for yourself, soothe some tension or relieve some stress - which also helps support your skin!
Using massage to help prevent stretch marks
The massaging action of rubbing in a moisturiser can boost circulation, and the American Association of Dermatologists recommends massage as a possible preventative technique. Massaging a natural, balanced moisturiser into stretch marks and stretching skin early and often may reduce their appearance or prevent new marks from forming. Regular care over a prolonged period is the best way of reducing these marks.
Ultimately, there may be nothing you can do to 100% guarantee you won’t get stretch marks, but there’s no reason not to take the best possible care of your skin.
Whatever approach you decide to take in response to your stretch marks, all the research points to prevention being easier and more likely than a cure - so taking steps as early as possible is always better than waiting.
If you’re pregnant, planning on becoming pregnant, or know your skin might be stretching rapidly for another reason, taking steps to look after your skin can be a really great way to feel better about the changes your body is going through. After all, if you’re pregnant, you’re moisturising for two!
Medical Disclaimer
Please note that this website does not provide medical advice. The material on this website are for informational purposes and not intended as a substitute for professional medical advice or treatment. As always seek the guidance of your doctor or other qualified health care provider with any questions you may have regarding your health. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.