Dr. Alicia Zalka on Rethinking Deodorant, Skin Science, and the Future of Body Care
In this Skin Anarchy episode, Dr. Ekta speaks with Dr. Alicia Zalka, board-certified dermatologist, educator, and founder of Surface Deep, about why body care — especially deodorant — deserves the same science-backed, ingredient-conscious approach as facial skincare. With over 30 years in medical dermatology, Dr. Zalka has transformed her clinical expertise into a mission to create pH-balanced, microbiome-friendly body products that go beyond masking odor to actually prevent it.
From Dermatology Practice to Deodorant Innovation
Dr. Zalka’s leap into product creation began by accident — literally forgetting her deodorant before a trip. Reaching for glycolic acid in her bathroom, she applied it under her arms as a quick fix and realized it kept her odor-free all day. This sparked the idea for Surface Deep: a dermatologist-developed anti-odorant that works with the skin’s natural balance instead of clogging pores or masking odor with fragrance.
Unlike conventional deodorants (which mask odor) or antiperspirants (which block sweat with aluminum), Surface Deep’s formulas maintain the skin’s acidic pH and support healthy bacteria using glycolic acid and postbiotic ferments — creating an environment where odor-causing bacteria can’t thrive.
Understanding the Skin Under the Arms
The underarm is intertriginous skin — thin, delicate, and prone to moisture buildup due to its fold structure. This makes it more vulnerable to irritation from waxes, baking soda, fragrances, and aluminum salts. The area houses a resident bacteria, Staphylococcus hominis, which actually helps prevent odor. Problems arise when moisture and irritation allow pathogenic bacteria to crowd out these beneficial microbes.
“Sweat is intentional — odor is preventable.”
Odor Science: It’s About Bacteria, Not Sweat
Sweat itself is odorless and produced by two gland types — eccrine and apocrine. Odor forms when certain bacteria (like Corynebacterium) break down sweat, producing compounds like ethyl alcohol. Killing all bacteria isn’t the answer — instead, the goal is to preserve beneficial strains while preventing overgrowth of odor-causing ones.
Why Most Deodorants Miss the Mark
Many deodorants rely on fragrance layering, occlusive waxes, and alkaline soaps that disrupt the skin’s acid mantle (pH ~5.5). This can delay the skin’s return to balance after cleansing and even worsen odor over time. Dr. Zalka’s approach is to:
- Avoid blocking sweat ducts unless medically necessary (as in hyperhidrosis)
- Maintain acidic pH to protect the microbiome
- Skip heavy occlusives that trap moisture and bacteria
- Avoid allergen-prone fragrances in leave-on products for sensitive areas
Glycolic Acid Done Right
Glycolic acid — an alpha hydroxy acid with the smallest molecular size — exfoliates dead cells, supports pH balance, and keeps skin smooth. While viral TikTok trends encouraged using glycolic toners under arms, Dr. Zalka cautions that formulation matters — especially for delicate fold areas. Surface Deep’s proprietary blend combines glycolic acid with soothing aloe and postbiotics for efficacy without irritation.
The “Stinky Seven” & Whole-Body Deodorant
Dr. Zalka identifies seven key odor-prone zones:
- Scalp/back of ears
- Underarms
- Under/between breasts
- Belly button
- Abdominal fold
- Groin
- Between toes
She supports the rise of whole-body deodorants — if they are gentle, pH-balanced, and microbiome-friendly — warning against simply applying more chemicals and perfumes to more body areas.
Final Takeaway
Dr. Zalka’s message is clear: body care deserves the same precision and respect as facial care. By maintaining the skin’s acid mantle, supporting healthy bacteria, and avoiding unnecessary occlusion or fragrance, we can achieve lasting odor prevention without compromising skin health.
“Body odor prevention begins in the shower — but it’s not about sterilizing your skin. It’s about keeping it balanced.”
🎧 Listen to the full episode to learn how Surface Deep is redefining the deodorant category through dermatology, microbiome science, and clean formulation.