Botox is not the standard treatment for nasolabial folds, and most injectors will recommend dermal fillers instead. When Botox is used in the muscles around the nasolabial area, the doses are small, typically 2 to 4 units per side, injected into specific muscles that contribute to the fold’s depth during facial movement. But understanding why so few units are used, and why Botox alone rarely solves the problem, is key to getting the result you actually want.
Why Botox Isn’t the Go-To for Nasolabial Folds
Nasolabial folds are primarily caused by volume loss in the midface and the pull of gravity on skin and fat pads over time. That makes them a structural problem, not just a muscular one. Botox works by relaxing muscles, which is effective for wrinkles that appear when you move your face (crow’s feet, forehead lines) but cannot fill in a crease that’s visible even when your face is at rest.
Dermal fillers are the standard treatment because they physically add volume beneath the fold, lifting the crease from underneath. Fillers also produce immediate visible results, while Botox takes days to take effect and addresses only the dynamic component of the line. For deep, static nasolabial folds, Botox on its own will not produce meaningful improvement.
When Botox Is Used Near Nasolabial Folds
There are specific situations where Botox plays a supporting role. If your nasolabial folds deepen noticeably when you smile or scrunch your nose, a small amount of Botox can soften that movement without erasing your expression entirely. The target is usually the levator labii superioris alaeque nasi, a muscle that runs alongside the nose and pulls upward when you smile or flare your nostrils. Published case reports describe injecting as little as 2 units of Botox into this muscle on each side, with noticeable improvement starting within a couple of days.
Another common approach involves treating the muscle that pulls down the corners of the mouth (the depressor anguli oris). When the mouth corners droop, it can exaggerate the appearance of lines running from the nose to the mouth. Relaxing that muscle with 2 to 4 units per side lifts the corners slightly and can reduce the overall severity of the fold. This works best when the downturned mouth is actually contributing to the problem, not when volume loss is the main driver.
Some practitioners combine both approaches, using small Botox doses in supporting muscles alongside filler placed directly into the fold itself. This combination addresses both the structural depth and the muscular deepening that happens with expression.
Risks of Botox Around the Mouth
The muscles around your mouth control smiling, chewing, drinking, and speaking. Even small amounts of Botox in this area carry functional risks that don’t exist with forehead or crow’s feet injections. Studies report that roughly half of patients treated with Botox in the lower face experience some mild difficulty with drinking, chewing, speaking clearly, or smiling naturally at the two-week mark.
Higher doses increase the likelihood of problems. The most common complaints include an uneven smile, trouble controlling liquids when drinking, accidentally biting the inside of your lip or cheek, and changes in how your voice sounds. These effects are temporary, lasting as long as the Botox remains active (typically 3 to 4 months), but they can be socially noticeable and frustrating in the meantime.
This is the main reason injectors keep doses so low in this region. There is very little margin between “enough to soften the fold” and “enough to interfere with normal facial function.” An experienced injector will often start conservatively, sometimes as low as 1 to 2 units per side, and have you return for a touch-up if needed rather than risk overcorrection.
Dynamic Versus Static Folds
The single most important factor in whether Botox will help your nasolabial folds is whether they’re dynamic or static. Dynamic folds appear or deepen when you move your face, like when you smile broadly, and soften or disappear when your face is relaxed. These are driven by muscle contraction, and Botox can meaningfully reduce them.
Static folds are visible all the time, even with a completely relaxed expression. These result from lost volume, thinning skin, and years of repeated folding in the same spot. Botox will not improve a static fold because the crease exists independent of muscle movement. If you can see the line clearly in a mirror with a neutral expression, filler is almost certainly the better option. If the line mainly bothers you in photos where you’re smiling, Botox may be worth discussing.
What to Expect From Treatment
If you and your injector decide Botox is appropriate for your nasolabial folds, the treatment itself is quick. You’ll receive one or two small injections per side using a very fine needle. The total dose for both sides is usually between 4 and 8 units, making this one of the lowest-dose Botox applications on the face.
Results begin to appear within 2 to 5 days and reach full effect around two weeks. The improvement is subtle: your smile lines won’t disappear, but they should look softer during expression. The effect lasts about 3 to 4 months before the muscle activity gradually returns. Because the doses are so small, some people find the results fade faster than they do with forehead Botox.
If your provider recommends combining Botox with filler, the filler handles the depth of the fold at rest while the Botox prevents the fold from creasing as sharply when you animate. This combination approach tends to produce the most natural-looking and longest-lasting improvement for moderate to deep nasolabial folds.