Armpit Stretch Marks: Causes, Risk Factors & Prevention

Is this an allergic reaction or a cut? 

Having ruled those options out, you may be dealing with armpit stretch marks. 

These small purple or red marks across your skin, formally known as “striae,” come along with the expansion of the skin. 

They’re a normal change to your body, especially if you’re growing muscle or your weight has fluctuated. Although they’re normal, armpit stretch marks won’t always make you feel the sexiest. 

In fact, many people are self-conscious about their stretch marks. Bodybuilders who push their limits to achieve their desired physiques, teens during puberty, and pregnant individuals all commonly get stretch marks.

This blog will walk you through the basics of armpit stretch marks and how to prevent or fade them. We will explore the causes of armpit stretch marks, good ways to prevent them, and what treatments you can use to fade stretch marks. 

What is a Stretch Mark?

First off, let’s explore the science of stretch marks. 

Stretch marks are formally called “striae.” 

This can refer to any kind of irregular lines that show up on your skin, occurring when the skin has stretched or shrunken too quickly. 

Typically, you’ll see red, reddish-brown, or purple marks that indicate new stretch marks. Older stretch marks that have faded over time will look white or pink, or can be a shade similar to your natural skin tone. 

Striae are considered a form of dermal scarring. The “dermis” or “derma” layer of your skin becomes damaged and stretches beyond its natural capacity. Along with armpit stretch marks, it’s common to see stretch marks on your: 

• Buttocks
• Hips
• Breast
• Thighs 
• Groin 
• Or bicep stretch marks.

Why Do I Have Armpit Stretch Marks? Common Causes

Armpit stretch marks or other marks in other areas can crop up for a few main reasons. These include:

1. You’re Building Muscle

When you experience quick gains in muscle size, like during weight training, your skin may not have enough time to stretch gradually. This can cause small tears to what’s called your “dermis,” the middle layer of your skin.

If your skin doesn't adapt quickly enough to your muscle gains, it can result in stretch marks. Make sure your muscle-building goals increase gradually so your skin doesn’t stretch excessively. 

2. You’ve Recently Experienced a Growth Spurt

During puberty, young people typically get taller and gain weight quickly.

Of course, humans need to grow, and puberty is an essential step in the pathway to adulthood. For the skin, however, rapid growth can leave your skin with stretch marks since your body is growing faster than your skin can keep up with. 

Generally, puberty lasts for about 2-5 years, so if you can, it’s a good idea to work toward stretch mark prevention during this time. 

3. You’re Going Through a Hormonal Shift 

Hormones can be truly confusing things. 

Throughout your life, natural fluctuations in your hormones can cause the texture of your skin to change or may influence how elastic it is. Things like skin dryness can all be influenced by hormones. 

This can result in armpit stretch marks as a not-so-great side effect. 

4. You’ve Gained or Lost Some Weight

Fluctuating body weight too quickly can also cause your skin to stretch beyond its normal capacity. 

It’s more common to see stretch marks when you gain weight, but rapid weight loss can also lead to the appearance of stretch marks. 

Basically, a quick weight loss, like you’d see on a crash diet, is confusing to your body. Your skin has a comfortable capacity at which it can stretch¸— after all, humans do need the space to grow as they age. 

Although 5 lbs of fat vs. muscle have very different spatial sizes, gaining either quickly will shock your body. 

A quick and significant change to your weight throws your body off. Your nervous system doesn’t have the chance to understand and adapt to the pace of your weight change. Your skin can’t stretch accordingly. As a result, you can see tears in your dermal layer that create stretch marks. 

6. You Have Stretch Mark Genes

Genetically, some people’s skin is programmed to be more or less elastic than others. If you naturally have skin that is drier or produces less collagen, you may be more inclined to stretch marks naturally. 

How Do I Get Rid of Armpit Stretch Marks? Treatment Options

So, if you’ve noticed some stretch marks on your armpits and would like to get rid of them, are there things you can do to fade stretch marks?

Here are a couple of options you can try to reduce the look of stretch marks on your armpits.  

1. Oil or Cream

As a starting point, it’s better to err on the side of a less invasive option. 

There’s mixed evidence on whether oil is an effective treatment for stretch marks, but most studies show that many oils can have some effect on fading scars.

One popular treatment is coconut oil, but there is no current evidence that coconut oil fades stretch marks. However, coconut oil acts as a sealant and moisturizer, holding existing water in to moisturize the skin. 

If you think skin dryness is a cause of your stretch marks, you can try using coconut oil to increase your skin's overall moisture, but it won’t fade existing armpit stretch marks. 

2. Laser Treatment 

Medical and aesthetic laser treatments can be used to help fade armpit stretch marks. 

Light therapy techniques are increasing in popularity, and lasers like Fraxel have been shown to repair skin damage as a non-invasive procedure.

Updates on fractional laser technology show good evidence that Fraxel and other similar treatments effectively fade skin conditions like photodamage, acne, and stretch mark scarring. 

Keep in mind that these treatments are expensive. If you don’t have a budget for laser treatment, focus instead on prevention rather than scar fading. 

3. Microneedling

Microneedling involves pricking your skin with tiny needles to signal that your body should produce more collagen and elastin. 

Collagen and elastin are natural proteins that contribute to your skin’s elasticity. When you get older, you produce less of these substances, but some people who experience more armpit stretch marks may have less elasticity in their skin due to genetics. 

To heal the micro-wounds, your body sends more collagen and elastin to the treatment areas, which can be beneficial if you’re struggling with armpit stretch marks. 

How Do I Prevent Armpit Stretch Marks? 

There’s no 100% guarantee that you’ll never get armpit stretch marks. However, many strategies actively contribute to the management of stretch marks. 

Here are a few of the best ways to prevent stretch marks on your armpits. 

Gradual Muscle Gain

If you’re just starting out in the gym, seeing those newbie gains come in can be super exciting. 

One study on strength development during strength training in strength-trained and untrained men actually found that newbie lifters could gain over 5x as much strength in 21 weeks as those with prior training histories. Those gains come not only with strength but muscle, too. 

No, don’t take this as a sign that you’re going to get jacked instantly the second you touch a weight rack. But your early days or months in the gym can be a significant time for transforming your body with muscle. 

If you’re new to working out, focus on sustained progressive overload (or increasing your workout routine intensity incrementally each session). Even if you’re feeling strong, don’t overdo it. 

Allowing yourself to progress at a reasonable pace puts less demand on your skin to stretch at the quick rate that your muscles are growing. Simple, lightweight chest workouts with dumbbells or chest isolation exercises can work the muscles around the armpits more gently than just going for that massive bench press straight away if you want to avoid skin stretching. 

The temptation to dirty bulk and get big fast might be nagging at you in the back of your head, but try to resist. Not only is slow progress better for avoiding injuries, but this is the type of progress you can actually hold onto to build better habits in the gym. 

If you find yourself over or underloading your weights as a newbie, you can always try Flex Fitness app as a free way to keep an eye on your weight loads and keep yourself accountable as you get used to working out effectively. 

Moisturize!

As you get older, maintaining your skin’s natural hydration levels and elasticity is one of the best preventive measures you can take against stretch marks. 

Creams and oils containing vitamin E and shea butter are good moisturizers, as a general rule. These can help improve the texture of your armpit skin and can stop more armpit stretch marks from forming.

Diet

Image: A healthy stirf fry with stretch mark fighting ingredients. 

Some nutrients are beneficial for overall skin health and can be a helpful measure if you’re prone to stretch marks. 

Try to incorporate foods high in: 

• Vitamin A: Try squash, carrot, spinach, sweet potato, bell pepper, beef liver, and broccoli. 
• Vitamin C: You’ll find this in citrus fruits, potatoes, strawberries, and bell peppers.
• Vitamin D: Include egg yolks, fatty fish, mushrooms, and cod liver oil.
• Vitamin E: Try almonds, peanuts, sunflower seeds, and pumpkin for more vitamin E. 
• Zinc: Opt for foods like red meat, seafood, poultry, and nuts to introduce more zinc to your diet. 
• Lean protein: You can find this in foods like chicken breast, beans, lentils, eggs, etc. 
  

All of these vitamins and nutrients, along with drinking enough water, can help you maintain the health of your skin so that you’re less prone to stretch marks. 

FAQ

Should I ask a dermatologist about stretch marks?

They typically don’t pose a threat to your health. However, if your stretch marks are causing you mental distress or negatively impacting your quality of life, you may want to consult a physician or other professional to discuss more permanent solutions. 

Can armpit stretch marks go away naturally? 

Stretch marks fade over time but often don’t disappear completely. Usually, faded stretch marks will lose the reddish or purple color that people find less attractive and become a pale or white color that is less noticeable. 

Does losing weight cause stretch marks?

Losing weight can cause stretch marks, just like weight gain. 

Why? 

What you’re dealing with in both cases is a dramatic change in body mass over a short period of time. Because of the shortened timeline, the skin also doesn’t have the time to adapt to quick weight loss. 

Just like with gaining muscle, slow and steady is your best option if you’re hoping to lose weight and avoid stretch marks. That way, you ensure your skin can “shrink” in time with the rest of your body. 

Why am I getting stretch marks if I’m not gaining weight?

If you notice stretch marks forming without any major weight change, it could be due to genetic or hormonal factors.   

Big Picture

Stretch marks are a natural occurrence for most people and can sometimes happen whether you like them. 

Armpit stretch marks can come from weightlifting. You may see these, especially if you’re bulking up your biceps, chest, or shoulders— all areas that sit around the armpit creases. 

Armpit stretch marks and stretch marks in general can be caused by:  

• Puberty 
• Pregnancy 
• Genetic Factors
• Hormonal Changes
• Skin Elasticity

To avoid armpit stretch marks, avoid excess body fat. 

You can eat a lean and protein-rich diet focused on essential nutrients. If supplements are something you’re considering for fat loss, read this guide: Does Creatine Help With Weight Loss?

If you’re looking to lose or gain weight, making small changes to your strength training program each week is your best bet. 

This allows you to put on muscle mass or lose body fat slowly so your skin can keep up as your body changes! 

References

Ahtiainen, J.P., Pakarinen, A., Alen, M. et al. Muscle hypertrophy, hormonal adaptations and strength development during strength training in strength-trained and untrained men. Eur J Appl Physiol 89, 555–563 (2003). https://doi.org/10.1007/s00421-003-0833-3

Bielfeldt S, Blaak J, Staib P, Simon I, Wohlfart R, Manger C, Wilhelm KP. Observer-blind randomized controlled study of a cosmetic blend of safflower, olive and other plant oils in the improvement of scar and striae appearance. Int J Cosmet Sci. 2018 Feb;40(1):81-86. doi: 10.1111/ics.12438. Epub 2017 Dec 12. PMID: 29094366.

Cantelli M, Camela E, Marasca C, Fontanella G, Blasio C, Fabbrocini G. Topical oil formulation of plant extracts and vitamins as effective treatment for stretch marks and xerosis-An observational longitudinal study. J Cosmet Dermatol. 2021 Apr;20 Suppl 1(Suppl 1):9-13. doi: 10.1111/jocd.14094. PMID: 33934473; PMCID: PMC8251840.

Oakley AM, Patel BC. Stretch Marks. [Updated 2023 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK436005/

Update on fractional laser technology. J Clin Aesthet Dermatol. 2010 Jan;3(1):42-50. PMID: 20725538; PMCID: PMC2921736.

Wollina, U., & Goldman, A. (2017). Management of stretch marks (with a focus on striae rubrae). Journal of cutaneous and aesthetic surgery, 10(3), 124–129. https://doi.org/10.4103/JCAS.JCAS_118_17