Ask Dr P: HELP! My dark underarms are getting darker with treatment?

 

What you're experiencing is not damage. It's not a chemical burn. It's not your skin "rejecting" treatment or getting worse.

 

What you're seeing is reorganisation.

 

And while I understand how unsettling it is to see temporary darkening in an area that already carries so much psychological weight, I want to walk you through exactly what's happening at the cellular level, because once you understand the physiology, this phase becomes far less frightening.

 

 

The paradox of treatment-induced darkening

 

Here's what most people don't realise about treating hyperpigmentation in areas like the underarms:

 

 

The skin often looks darker before it looks lighter.

 

 

This is not a flaw in the treatment. It's a feature of how skin renewal works, particularly in melanin-rich skin that has experienced chronic friction, occlusion, and barrier disruption.

 

Let me explain why.

The physiology of what you're actually seeing

 

1. Underarm skin is uniquely vulnerable

 

Axillary skin exists in a perfect storm of aggravating factors:

 

- High-friction environment: constant arm movement creates repetitive mechanical stress

- Occlusive microclimate: the area is naturally occluded, creating elevated temperature and humidity that disrupts barrier function[1]

- Apocrine gland density: high concentration of sweat glands means constant moisture exposure

- Chronic low-grade inflammation: from shaving, waxing, friction, and previous product use

- Hair follicle density: each follicle represents a potential site of inflammation and post-inflammatory pigmentation

 

When skin experiences chronic irritation, even subclinical irritation that you cannot see or feel, melanocytes become hyperactive as a protective response. This is the skin's evolutionary defence mechanism: produce more melanin to shield DNA from damage[2].

 

But here's the critical part: that melanin doesn't just sit in the basal layer. It gets transferred to keratinocytes throughout the epidermis, and when barrier function is compromised, those pigmented cells don't shed normally.

 

 

2. The compacted stratum corneum phenomenon

 

In chronically irritated skin, the outermost layer (stratum corneum) becomes thickened and compacted, a process called hyperkeratosis[3]. Think of it as the skin building a protective wall of dead cells that refuse to shed properly.

 

This thickened layer:

 

- Contains accumulated melanin from months or years of previous inflammation

- Has irregular surface topology that scatters light differently (making pigmentation appear darker)

- Creates a physical barrier that prevents even penetration of treatment ingredients

- Masks the true texture and tone of the skin beneath

When you introduce a treatment formula designed to normalise skin turnover, like Éclair, which contains humectants, gentle exfoliants, and melanogenesis modulators, you're essentially asking that compacted layer to reorganise and shed.

 

3. The desquamation cascade

 

Here's where it gets interesting.

 

Normal skin cell turnover takes approximately 28-40 days in young adults, but can extend to 45-60 days in chronically thickened skin[4]. When you introduce active treatment, you're accelerating this process.

 

What happens is:

Phase 1 (Weeks 1-3): Loosening and migration

- Corneocyte adhesion weakens as desmosomes break down

- Old, pigmented keratinocytes begin migrating upward

- The stratum corneum temporarily becomes MORE visible as cells loosen but haven't yet shed

- Light scattering changes, making the area appear darker or more textured

Phase 2 (Weeks 3-6): Uneven shedding

- Desquamation occurs in patches rather than uniformly

- Some areas shed faster than others, creating temporary unevenness

- The skin may feel rough as cells are in various stages of detachment

- This is the phase where most people panic and stop treatment

Phase 3 (Weeks 6-12): Normalisation

- A newer, more even stratum corneum emerges

- Barrier lipids reorganise with improved lamellar structure

- Melanin distribution becomes more uniform

- Texture smooths and tone begins to lighten

You are currently in Phase 2. The most visually confronting phase. The phase that requires trust in the process.

4. Why melanin-rich skin shows this more prominently

This phenomenon is particularly pronounced in skin with constitutive melanin because:

- Greater melanin density: more melanin means more visible contrast during the shedding phase[5]

- Longer pigment retention: melanin in darker skin types persists longer in the upper epidermis

- Enhanced post-inflammatory response: skin of colour has more reactive melanocytes that respond to even minor inflammation with increased pigment production[6]

- Visible texture changes: thickening and roughness are more apparent against darker skin tones

This is not a limitation of your skin. It's a physiological reality that requires patience and proper expectation-setting.

 

What you're NOT seeing

Let me be clear about what this is not:

Not a chemical burn

- No blistering, erosion, or raw skin

- No sharp, persistent pain

- No immediate redness, grayness/violaceous changes WITH discomfort or swelling

 

Éclair is pH-balanced and formulated specifically to avoid acid burns

Not new hyperpigmentation

- This is old melanin becoming visible as it migrates upward

- New melanin synthesis takes weeks to manifest

- The timeline doesn't match melanogenesis kinetics

Not an allergic reaction

- No urticaria (hives), no systemic symptoms

- No progressive worsening beyond the textural phase

- Normal barrier recalibration, not immune response

The recalibration protocol

If you're in this phase, here's how to support your skin through it:

Reduce frequency temporarily

1. Move to once-daily application for 7-10 days

2. Apply only to completely dry skin

3. Allow your barrier to stabilise

Add barrier support

1. Use a simple, fragrance-free restorative cream at night (I recommend Avène Cicalfate or La Roche-Posay Cicaplast or even a thin layer of Vaseline after moisturiser)

2. This provides lipids and prevents transepidermal water loss during reorganisation

Remove additional irritants

1. Pause shaving or waxing

2. Avoid scrubs, additional acids, or friction

3. Wear loose, breathable clothing

Watch for true warning signs

- Worsening pain (not mild sensitivity)

- Open skin or oozing

- Persistent redness or grayness that doesn't resolve

- Systemic symptoms

If any of those occur, stop use and get in touch with our support team at support@lorientofficial.com where Dr P will provide tailored support.

Why I'm telling you this

Because the beauty industry has conditioned us to expect immediate, linear improvement. Glowing skin in 7 days. Visible brightening overnight. Transformation in a weekend.

But real physiological change doesn't work that way.

When you're addressing chronic skin changes, particularly in an area as complex as the underarms, you're working against years of accumulated damage. The skin needs time to shed, rebuild, and reorganise. That process is not always aesthetically pleasing in the middle.

This is why I built LORIENT on a philosophy of pleasure over pressure. Not because results don't matter, but because sustainable results require patience, education, and trust in your skin's capacity to heal when given the right support.

Your underarms looking darker at week three doesn't mean the treatment failed. It means it's working exactly as the physiology dictates.

The clinical evidence

For those who want to understand the mechanisms more deeply, here are the key references:

Clinical References

1. Werschler WP, Trookman NS, Rizer RL, et al. Enhanced efficacy of a facial hydrating serum in subjects with normal or self-perceived dry skin. J Clin Aesthet Dermatol. 2011;4(6):51-55.
2. Lin JY, Fisher DE. Melanocyte biology and skin pigmentation. Nature. 2007;445(7130):843-850. doi:10.1038/nature05660
3. Pappas A. Epidermal surface lipids. Dermatoendocrinol. 2009;1(2):72-76. doi:10.4161/derm.1.2.7811
4. Weinstein GD, McCullough JL, Ross P. Cell proliferation in normal epidermis. J Invest Dermatol. 1984;82(6):623-628. doi:10.1111/1523-1747.ep12261462
5. Taylor SC. Skin of color: biology, structure, function, and implications for dermatologic disease. J Am Acad Dermatol. 2002;46(2 Suppl):S41-S62. doi:10.1067/mjd.2002.120790
6. Davis EC, Callender VD. Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. J Clin Aesthet Dermatol. 2010;3(7):20-31.
7. Verdier-Sévrain S, Bonté F. Skin hydration: a review on its molecular mechanisms. J Cosmet Dermatol. 2007;6(2):75-82. doi:10.1111/j.1473-2165.2007.00300.x
8. Elias PM. Stratum corneum defensive functions: an integrated view. J Invest Dermatol. 2005;125(2):183-200. doi:10.1111/j.0022-202X.2005.23668.x
9. Draelos ZD. The science behind skin care: moisturizers. J Cosmet Dermatol. 2018;17(2):138-144. doi:10.1111/jocd.12490
10. Nouveau-Richard S, Yang Z, Mac-Mary S, et al. Skin ageing: a comparison between Chinese and European populations. J Dermatol Sci. 2005;40(3):187-193. doi:10.1016/j.jdermsci.2005.06.006

 

Have a question for Dr P? Submit it via email to support@lorientofficial.com. Selected questions will be featured in future blog posts.

Disclaimer: This content is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider for personalised treatment recommendations.