Dark Underarms from deodorant (hyperpigmentation causes)

Understanding Dark Underarms from Deodorant, and Why We Choose Magnesium

If you have ever noticed darkening under your arms, you are not alone. It is something many people experience at different stages of life, and it can feel frustrating, especially when you are doing all the “right” things. At Scence, we always like to take a step back, understand what is really going on, and then choose the gentlest, most supportive way forward.

What Causes Dark Underarms?

Dark underarms are usually a form of hyperpigmentation. This simply means that the skin is producing more melanin, the pigment that gives skin its colour, in response to certain triggers.

In the underarm area, those triggers are often everyday things:

• Friction from clothing or skin rubbing
• Shaving or hair removal
• Irritation from products
• Build-up of dead skin cells
• Sometimes hormonal changes

The skin here is delicate and more reactive than we often realise. When it becomes irritated, even subtly, it can respond by producing more pigment as a protective mechanism.

The Role of Deodorant

Deodorant is something we use daily, so it can play a surprisingly important role in how the skin under our arms behaves.

Some traditional and even “natural” deodorants rely on bicarbonate of soda (also known as baking soda) to neutralise odour. It is very effective at this, but it is also quite alkaline, with a pH of around 8 to 9.

Your skin, on the other hand, is naturally slightly acidic, typically around pH 4.5 to 5.5. This acidity is part of what keeps the skin barrier healthy and balanced.

When something more alkaline is applied regularly, it can disrupt that balance.

Why pH Matters More Than We Think

The skin’s slightly acidic environment supports what is known as the acid mantle. This helps:

• Maintain the skin barrier
• Support a healthy microbiome
• Protect against irritation and inflammation

When that balance is disturbed, even gently but repeatedly, it can lead to dryness, sensitivity, and low-level inflammation. Over time, this kind of ongoing irritation can contribute to hyperpigmentation.

So while bicarbonate of soda can be very good at controlling odour, it is not always the kindest option for long-term skin health, especially in such a sensitive area.

A Gentler Approach with Magnesium

This is why, at Scence, we chose to work with magnesium instead.

Magnesium compounds, such as magnesium hydroxide, are effective at neutralising odour by creating an environment where odour-causing bacteria struggle to thrive. But they do this in a much gentler way.

From a formulation perspective, magnesium is:

• Closer to the skin’s natural pH
• Less likely to disrupt the acid mantle
• Generally better tolerated by sensitive skin

This means we can support freshness without pushing the skin out of balance.

Supporting Skin, Not Fighting It

When we think about underarm care, we try to shift the mindset slightly. Rather than “fighting” odour or moisture, we look at how we can support the skin so it can do its job well.

Healthy, balanced skin is less likely to become irritated. And when irritation is reduced, one of the key triggers for hyperpigmentation is also reduced.

It is not about a quick fix, but about creating the right conditions for the skin to gradually return to a more even tone.

Small Changes That Make a Difference

If dark underarms are something you are experiencing, a few gentle changes can really help over time:

• Choosing a deodorant that supports the skin barrier, like those from Scence
• Being mindful with shaving, using a sharp blade and a soothing product
• Wearing breathable fabrics to reduce friction
• Gently exfoliating to prevent build-up of dead skin cells

These are small, manageable steps, but together they can make a meaningful difference.

Patience and Kindness to Your Skin

One of the most important things to remember is that hyperpigmentation takes time to develop, and it also takes time to fade. Skin renewal is a gradual process.

By reducing irritation and supporting the skin’s natural balance, you are giving your skin the best possible chance to recover.

Final Thoughts

Dark underarms are not a flaw, they are often just a sign that the skin has been under a little stress. With the right care, that can change.

At Scence, choosing magnesium over bicarbonate of soda is part of our wider philosophy. We are not looking for the strongest or most aggressive solution. We are looking for the kindest one that works.

Because when you support your skin, rather than challenge it, it has an incredible ability to find its balance again.