Choosing the right undershirt material can have a significant impact on your skin’s health, particularly if you are prone to acne or excessive sweating. Undershirts made of synthetic materials can exacerbate sweat, leading to increased bacterial growth and acne. Which materials to wear if you have acne problems and which one to avoid?
An undershirt can worsen sweat and cause acne if you wear an undershirt made of synthetic materials and sweat a lot. I recommend undershirts that are made of natural materials that breathe and absorb sweat. Acne is caused when bacteria get trapped in pores and increased sweating only worsens it.
In the rest of this post, you’ll find out if undershirts really do cause acne, and which materials are best to prevent acne and excessive sweating.
Does an undershirt cause acne?
Undershirts made of natural materials should not cause acne. Acne on the back occurs when the skin is wet, irritated and lacks air for a long time. Natural materials such as cotton and merino wool are healthy for your skin because they are breathable, comfortable and absorb moisture.
Back acne, or “backne”, occurs when pores fill up with oil, sweat and dead skin, causing bacteria to get trapped in our skin. Sweat and increased rubbing of wet clothes against the skin can make acne worse. The first step to avoiding acne is to choose clothes that are in direct contact with the skin.
The best materials for skin health are those that breathe well and wick and absorb sweat. A good quality undershirt should keep your skin dry for as long as possible. I therefore recommend choosing natural materials (cotton, merino wool or bamboo). Avoid undershirts that are mainly made of synthetic materials (polyester, elastane), as these materials do not absorb sweat, but hold sweat and heat against the skin.
When choosing a undershirt, the material mix should be at least 60% natural materials. Read the full comparison of cotton and polyester undershirts.
Does undershirts make sweat worse?
An undershirt can make sweating worse if it is made of materials that do not breathe and do not absorb and wick sweat away from the skin. In this case, sweat accumulates on the skin, causing further heating of the skin and increasing perspiration, the result is increased smells and odors.
Synthetic materials promote perspiration because they do not absorb sweat. As a result, sweat accumulates on the skin, which heats the skin, leading to increased perspiration. If the undershirt absorbs sweat, the skin stays drier for longer, does not overheat and rubbing the undershirt against the skin does not cause acne.
Wear natural underwear instead of synthetic materials, as they absorb sweat and keep your skin drier for longer. This is why it is a good idea to wear an undershirt even in summer, to avoid visible sweat stains on your outer clothing. The most recommended shape of undershirt is a T-shirt, but it is not a good idea to use a plain T-shirt. There are 9 reasons why.
Sleeves absorb sweat better, as this is where we sweat the most. Some undershirts are even tailored to have padded underarm areas to absorb more sweat.
What materials are bad for acne?
Synthetic materials are not suitable if you have acne. Synthetic materials such as polyester and elastane absorb sweat poorly and trap bacteria and odors. This leaves the skin wet and full of bacteria, leading to acne all over the body, most commonly on the back.
The undershirt should be made of natural materials. Why are natural materials the best? Because they breathe well, are good for skin health, absorb sweat and therefore keep the skin dry for longer. Natural materials do not trap bacteria and odors, so your skin will be clean even when your undershirt is soaked.
| Natural materials | Synthetic materials | |
| Breathable | ✅ | ✅ |
| Absorb sweat | ✅ | ❌ |
| Soft | ✅ | ❌ |
| Sweat-wicking | ✅ | ✅ |
| Odor resistant | ✅ | ❌ |
How to take care of undershirt if you sweat a lot?
If you sweat a lot, your undershirt accumulates a lot of bacteria that are produced when sweat comes into contact with your skin. This also causes odours, which is why we need to wash our undershirts every day, or every time we sweat.
The bacteria that accumulate on the undershirt can be destroyed by washing in warm water at 140°F or 60°C. This is the most ideal temperature for washing because at this temperature the bacteria are destroyed and the undershirt does not shrink. Washing at 190°F or 90°C may cause the undershirt to shrink because the hot water damages the fibres of the undershirt, which will make it last for less time. Here you can find out what are the signs to throw away your undershirt and how many undershirts you should have in your wardrobe.
| Wash Type | Temperature Range |
|---|---|
| Cold Wash | Below 30°C (86°F) |
| Warm Wash | Between 30°C (86°F) and 60°C (140°F) |
| Hot Wash | 90°C (140°F) and above |
If you sweat a lot, washing your undershirt in cold water (86°F or 30°C) will not kill all the bacteria because the water does not reach a high enough temperature.