Understanding the Science: How Numbing Creams Work
Topical anesthetic creams function by interrupting the nerve signals that transmit pain sensations to the brain. The most common active ingredient, lidocaine, achieves this by blocking the influx of sodium ions into the nerve membrane. This prevents the initiation and conduction of electrical impulses, effectively dulling the sensation of pain. Other agents like tetracaine and prilocaine are also used, sometimes in combination with lidocaine to create a more potent effect, such as with EMLA (Eutectic Mixture of Local Anesthetics).
The Pharmacology of Lidocaine and Other Agents
Lidocaine works quickly to numb the superficial layers of the skin. However, its ability to penetrate deeper layers, and the duration of its effect, are significantly influenced by several factors. When applied as a cream, the anesthetic must first pass through the outermost layer of the skin, the epidermis, to reach the nerve endings in the dermis below. The formulation of the cream, whether it's an oil-in-water emulsion like EMLA or a liposomal preparation, affects its absorption rate and depth.
Penetration vs. Tattoo Needle Depth
For a tattoo to be permanent, the ink must be deposited into the dermis, the layer of skin directly beneath the epidermis. Tattoo needles typically penetrate the skin to a depth of about 1.5 to 2 millimeters to reach this layer. With the right application technique and sufficient time, numbing creams can easily penetrate deep enough to numb this crucial area, providing effective pain relief during the tattooing process. The maximal penetration depth of up to 5mm observed in clinical studies for EMLA cream is more than enough to cover the required tattooing depth.
Factors Influencing How Deep Tattoo Numbing Cream Goes
Achieving the maximum numbing effect is a science in itself. Several key variables influence how deep the anesthetic penetrates and how long it lasts. Neglecting any of these can lead to disappointing or uneven results.
- Application Thickness: A thick, generous layer is necessary for proper absorption. Unlike regular lotion, numbing cream should not be rubbed in completely until it disappears. A thick layer (around 2-3mm) should be visible on the skin's surface to facilitate absorption.
- Occlusion: Covering the applied cream with an occlusive dressing, such as plastic wrap, is critical. This prevents the cream from drying out and creates a moist, warm environment that significantly increases the penetration of the active ingredients into the deeper layers of the skin.
- Application Time: The duration the cream is left on before the procedure directly correlates with penetration depth. While some surface numbing may occur in a shorter time, achieving a deep numbing effect often requires at least 60 to 90 minutes of application.
- Skin Location: The thickness and composition of skin vary across the body. Areas with thicker skin, such as the elbows, knees, and ribcage, may be more challenging to numb effectively, and the numbing effect may wear off faster.
- Added Vasoconstrictors: Some numbing creams contain vasoconstrictors like epinephrine, which constrict blood vessels. This helps to slow the absorption of the anesthetic into the bloodstream, prolonging the duration of the numbing effect and reducing swelling and bleeding.
Proper Application for Maximum Depth
To ensure your numbing cream works as effectively as possible, follow these steps meticulously:
- Clean and Exfoliate: Wash the area to be tattooed with a mild antibacterial soap and gently exfoliate to remove any dead skin cells or oils that could impede absorption. Pat the area completely dry.
- Apply a Thick Layer: Using a gloved hand or clean utensil, apply a thick, even layer of the numbing cream, extending about a half-inch beyond the planned tattoo area. Do not rub it in fully.
- Occlude with Plastic Wrap: Tightly cover the entire area with plastic wrap. This is a crucial step that enhances the numbing effect and prevents the cream from drying out.
- Wait for the Full Duration: Leave the cream on for the recommended time, usually 60 to 90 minutes, to allow for maximum penetration.
- Wipe and Begin: Just before the tattoo artist is ready to begin, remove the plastic wrap and thoroughly wipe off all the cream with a clean paper towel. Any residue can interfere with the stencil and the ink process.
Comparison: Maximizing Numbing Effects
| Factor | Impact on Penetration Depth | Pro Tip |
|---|---|---|
| Application Thickness | A thicker layer ensures more anesthetic is available to penetrate the skin. | Apply a thick, visible layer—think cake frosting, not moisturizer. |
| Occlusion (Plastic Wrap) | Creates a moist, warm environment that increases absorption dramatically. | Always cover the applied cream with plastic wrap for the entire duration. |
| Time | Longer application time (up to 90-120 minutes) allows for deeper penetration. | Schedule your application time with your tattoo appointment to wait for the full duration. |
| Skin Location | Thicker skin areas and those with higher blood flow may see less or shorter effects. | For tough areas like ankles or elbows, you may need a slightly longer application time. |
| Active Ingredient | Potency and formulation (e.g., lidocaine % or inclusion of prilocaine) affect results. | Choose a cream with an appropriate concentration for tattooing, like up to 5% lidocaine. |
Potential Risks and Limitations
While numbing creams can be highly effective, it's important to be aware of potential risks. Some people may experience localized side effects like redness, swelling, or allergic reactions. An expert advises performing a patch test days before the appointment to check for adverse reactions. A significant concern with improperly used high-concentration numbing cream is the risk of systemic toxicity if absorbed heavily over a large area, especially on compromised skin. The FDA has issued warnings about this, especially concerning covering large areas with occlusion. Additionally, some artists report that numbing cream can temporarily alter the skin's texture, making it feel rubbery or slippery, which can affect the tattooing process and ink saturation.
Conclusion: Maximizing Your Numbing Cream's Potential
Ultimately, the depth of tattoo numbing cream penetration is a function of both the product's formulation and the user's application method. While the cream can certainly reach the dermal layer where tattooing occurs, its effectiveness is not guaranteed without following proper protocol. By applying a thick, occluded layer and waiting for the recommended time, you can significantly increase the chances of a more comfortable tattooing session. However, it's always best to have an open conversation with your tattoo artist about using numbing creams, as their experience and technique are also vital to a successful outcome.
For more in-depth medical information on topical anesthetics, visit the National Library of Medicine.
