A mammogram is a specialized X-ray used to screen for breast cancer. For accurate results, the breast and underarm area must be completely free of certain substances. Avoiding deodorant before the procedure is mandatory to ensure the quality of the resulting image. This rule is based on the physical science of how the imaging technology works and what cosmetic products contain.
The Physical Science: Why Deodorant Appears on the Image
Mammography uses a low-dose X-ray beam to create images of the breast’s internal structures, relying on different tissues absorbing X-rays to varying degrees. Dense materials prevent X-rays from passing through, making them appear bright white on the film, while less dense materials like fat appear darker or gray.
The metallic compounds found in many underarm products are highly dense, meaning they absorb the X-rays effectively. When this residue is present on the skin, it creates bright white spots known as artifacts on the mammogram image. These artifacts can interfere with the radiologist’s ability to accurately read the scan.
These bright white spots mimic the appearance of microcalcifications within the breast tissue. Microcalcifications are small calcium deposits that can sometimes indicate early-stage breast cancer, particularly ductal carcinoma in situ. Since the metallic residue is visually indistinguishable from genuine calcifications, the artifact can lead to an unnecessary call-back for additional imaging or a biopsy.
Common Products and Ingredients That Cause Artifacts
The primary culprits for image interference are antiperspirants, which are designed to block sweat glands. These products contain metallic compounds, most commonly aluminum compounds like aluminum chlorohydrate or aluminum zirconium, which are the active ingredients that clog the sweat ducts. The high density of these aluminum particles causes them to show up prominently on the X-ray.
Standard deodorants, which only mask odor, can also contain metallic or dense ingredients. Body powders, shimmering lotions, creams, and some natural deodorants containing mineral-based compounds can also leave a dense residue. Any product applied to the armpit, chest, or breast area that contains tiny, dense particles should be avoided to prevent image distortion.
What to Do If You Arrive Wearing Deodorant
Forgetting the rule and applying deodorant out of habit is a common occurrence, and patients should not feel embarrassed. If you realize you have applied a product, you should inform the technologist immediately upon arrival. The appointment will not typically be canceled or rescheduled because of this oversight.
The imaging center staff will provide cleansing wipes or towelettes to remove the residue from the underarm area. It is necessary to thoroughly clean the entire armpit and the surrounding chest area to ensure all particles are removed before the X-ray is taken. Once the area is clean, the screening can proceed without delay, ensuring the resulting images are clear and diagnostic.
Preparation and Alternatives for Mammogram Day
Preparation involves ensuring a thorough cleaning of the area the morning of the procedure. It is recommended to wash the underarm and breast area well using only mild soap and warm water in the morning shower. After washing, no further products—including lotions, powders, perfumes, or creams—should be applied to the chest or armpits.
For individuals concerned about body odor, there are a few alternatives. Some people find that simply washing the area well and wearing a clean shirt is sufficient for the short duration of the appointment. Other options include bringing a product-free towelette to use right before the exam, or packing your regular antiperspirant to apply immediately after the screening is complete. Scheduling the appointment early in the day can also help minimize the time spent without a product.