Skin tags can and often do turn black or dark purple before they fall off, and the color change almost always signals that the tag has lost its blood supply. A skin tag is a small, benign growth that stays alive because a thin stalk of tissue feeds it with blood. When that blood flow gets interrupted, whether naturally through twisting or deliberately through treatment, the tissue dies and darkens. The darkened tag then dries out over a period of days to weeks and eventually detaches. While this process is usually harmless, certain color changes in skin growths do warrant a closer look.
Why a Skin Tag Turns Black
Every skin tag is connected to the body by a narrow stalk called a peduncle. That stalk contains tiny blood vessels that keep the tag’s tissue alive. When those vessels get pinched or blocked, oxygen stops reaching the cells, and the tissue begins to die. Dermatologists call this process infarction or necrosis, but the visible result is simple: the tag shifts from its usual skin-toned or pinkish color to dark red, then purple, and eventually black. The darkening is essentially the same thing that happens when any small piece of tissue loses circulation. The dead cells dry out, the tag shrinks, and it drops off or can be brushed away with minimal effort.
The most common natural trigger for this is torsion, where the tag twists on its stalk. Because many skin tags dangle from a very thin connection point, everyday movement, clothing friction, or even sleeping on the area can rotate the tag enough to kink its blood supply. Larger, more pendulous tags are especially prone to this because their weight makes twisting more likely. You might wake up one morning and notice a tag that was flesh-colored yesterday has gone dark overnight. In most cases, this means it twisted while you slept, the blood flow stopped, and the tissue is already dying.
Darkening After Professional Treatment
If you have a skin tag removed by a doctor, the tag turning black is not just expected but actually the intended outcome with certain methods. Cryotherapy, which uses liquid nitrogen to freeze the tag, works by destroying the cells through extreme cold and cutting off local blood supply. After freezing, the tag swells slightly, darkens over the following days, and then shrivels and falls off, usually within one to three weeks. Electrosurgery achieves a similar end through heat, using a high-frequency electrical current to burn and remove the growth.
A randomized clinical trial comparing cryotherapy and electrosurgery for several benign skin growths, including skin tags, confirmed that both methods are effective at destroying the tissue, with the tag shrinking and eventually detaching after treatment.1PubMed Central. Evaluation and Comparison of the Efficacy and Safety of Cryotherapy and Electrosurgery in the Treatment of Sebaceous Hyperplasia, Seborrheic Keratosis, Cherry Angioma, and Skin Tag: A Blinded Randomized Clinical Trial In both cases, the dark coloring that appears post-treatment is simply dead tissue drying out. It typically resolves on its own without intervention.
Ligation is another common approach, sometimes done at home with a small band or thread tied tightly around the base of the tag. The mechanism is the same: the tie strangles the blood supply, the tissue dies and darkens, and the tag falls off within several days. Over-the-counter skin tag removal kits often work on this principle, providing small rubber bands designed to be looped around the stalk. When the method works as intended, the progression from normal color to dark to black to detachment is exactly what you should see.
How Long the Process Takes
The timeline varies depending on how the blood supply was interrupted. A skin tag that has twisted naturally and lost its circulation completely can turn black within hours and fall off in a few days. After cryotherapy, most tags darken within the first two to five days and detach within one to three weeks. With ligation, whether done professionally or at home, the process usually takes about a week, though larger tags can take longer because more tissue needs to lose its blood supply and dry out.
During this period, you might notice some mild tenderness, slight swelling, or a small amount of clear fluid around the base. These are normal signs of the tissue dying and the body beginning its cleanup work. What you should not see is spreading redness, warmth, pus, or increasing pain radiating beyond the tag itself, all of which could signal an infection. If the area around a darkened skin tag starts looking inflamed rather than simply drying out, that is worth a call to your doctor.
When a Dark Skin Tag Deserves Medical Attention
Most skin tags that turn black are going through the straightforward process described above and pose no health risk. But there are situations where a darkening or changing skin growth should be examined by a professional.
The first is when you are not sure the growth is actually a skin tag. Skin tags are extremely common and mostly benign, but research using advanced imaging techniques has shown that growths clinically resembling skin tags can occasionally harbor skin cancers.2Wiley Online Library. Skin tags imaged by reflectance confocal microscopy, optical coherence tomography and multispectral optoacoustic tomography at the bedside A melanoma, basal cell carcinoma, or seborrheic keratosis can sometimes mimic the appearance of an innocent skin tag, particularly in the early stages. If a growth you assumed was a skin tag starts changing color without an obvious trigger like twisting or treatment, or if it changes shape, bleeds spontaneously, or develops irregular borders, it is worth having it examined.
The second scenario is when a skin tag turns dark but does not fall off. A tag whose blood supply was truly cut off will dry, shrivel, and detach. If a growth darkens but stays firmly attached, grows back, or seems to be getting larger rather than smaller, that pattern does not match normal skin tag infarction and should be evaluated.
A helpful general rule: a skin tag that twists, turns dark, and then shrivels up and falls off on a predictable timeline is following the expected path. A skin growth that changes color in a way that does not match that timeline, or that has features you do not recognize, is worth getting checked out.
Why Skin Tags Form in the First Place
Understanding what causes skin tags helps explain why some people get dozens of them while others never develop a single one. The growths tend to appear in areas where skin rubs against skin or clothing: the neck, armpits, under the breasts, groin folds, and eyelids. Friction is widely considered a major trigger, which is why skin tags are more common in people who are overweight, as more skin-on-skin contact occurs in body folds.
But friction alone does not tell the whole story. Research has consistently linked skin tags with metabolic disturbances, particularly insulin resistance. A study examining the metabolic profiles of skin tag patients found that insulin resistance, elevated blood sugar, higher cholesterol, and elevated triglycerides were all significantly more common in people with skin tags compared to those without them.3PubMed. The metabolic profile in patients with skin tags The researchers suggested skin tags could be a visible marker for increased cardiovascular risk. A separate study confirmed a direct association between skin tags and insulin resistance scores, with those having the highest resistance levels being roughly seven and a half times more likely to have skin tags.4Anais Brasileiros de Dermatologia. Association between skin tags and insulin resistance
This does not mean everyone with skin tags has diabetes or heart disease. It means that if you are developing multiple skin tags, particularly in middle age, it may be worth having your blood sugar and cholesterol checked. The tags themselves are harmless, but they can sometimes be an early visible hint that metabolic changes are happening beneath the surface.
Pregnancy is another well-known trigger, likely related to hormonal shifts and the increased levels of growth factors circulating during that period. Skin tags that appear during pregnancy sometimes resolve on their own after delivery, though many persist.
The HPV Question
Whether human papillomavirus plays a role in skin tag formation has been debated in dermatology circles for years, and the evidence remains genuinely contradictory. One study using PCR testing found mucosotropic HPV types (specifically HPV 6 and 11, the same low-risk strains associated with genital warts) in nearly half of the skin tag samples tested, while the surrounding normal skin tested negative for all HPV DNA.5PubMed. Human papillomavirus and skin tags: Is there any association? That result suggests HPV might contribute to the growth of at least some skin tags.
However, another study looking for both low-risk and high-risk HPV subtypes in skin tags found essentially no HPV in the tag samples at all and concluded there was no significant relationship between the virus and skin tag formation.6PubMed Central. An Association of Human Papillomaviruses Low Risk and High Risk Subtypes with Skin Tag The flatly opposite findings likely reflect differences in the populations studied, the HPV testing methods used, and possibly geographic variation in HPV prevalence. As things stand, HPV is not considered a primary cause of skin tags by most dermatologists, though it may play a supporting role in some cases.
The Risks of Removing Skin Tags at Home
The fact that a skin tag can safely fall off on its own after losing its blood supply sometimes encourages people to try forcing the process along at home. Tying off a small tag with clean thread or dental floss, while not typically recommended by doctors, is a relatively low-risk method when the growth is clearly a skin tag and the stalk is thin enough to be ligated effectively. The bigger concern is the wave of over-the-counter and internet-marketed skin tag removal products that promise painless results.
A review of adverse events linked to unapproved mole and skin tag removal products documented serious injuries including burns, pain, ulceration, and in some cases permanent scarring and disfigurement.7PubMed Central. Serious Skin Injuries Following Exposure to Unapproved Mole and Skin Tag Removers Many of these products contain caustic chemicals that do not discriminate between the tag and the healthy skin around it. The irony is that the skin tag itself would have been harmless, but the attempt to remove it left a scar or wound that was far worse than the original bump.
Cutting a skin tag off with scissors or nail clippers is another popular home method, and while small tags often come off cleanly this way, the risks include infection, bleeding that is harder to stop than expected (skin tags on the neck and face can bleed surprisingly well), and removing something that turns out not to be a skin tag. If you do choose to remove a tag at home, keep the area clean, use sterilized tools, and pay attention to any signs of infection afterward. For tags in sensitive areas like the eyelids or genitals, or for any growth you are not entirely sure about, professional removal is the safer choice.
Skin Tags That Come Back
One frustration people notice is that even after a skin tag successfully falls off, whether naturally or through treatment, new tags often appear in the same general area. This happens because the underlying factors that led to the original tag, such as friction, insulin resistance, and hormonal influences, have not changed. Removing the tag itself does not address the environment that produced it.
People who develop skin tags in friction-prone zones often find that reducing friction helps slow the recurrence. Wearing softer fabrics, keeping skin folds dry, and managing body weight can all reduce the mechanical irritation that promotes tag growth. For those whose skin tags are linked to insulin resistance, improving metabolic health through diet, exercise, or medication has the potential to reduce the number of new tags that appear, though this has not been studied in large controlled trials. The metabolic connection is well-documented,3PubMed. The metabolic profile in patients with skin tags but whether treating the metabolic issue directly translates to fewer skin tags remains more of a clinical observation than a proven intervention.
If you find yourself developing many new skin tags in a short period, particularly if this is a new pattern for you, it may be worth mentioning to your doctor. A sudden crop of skin tags can occasionally accompany hormonal changes, rapid weight gain, or the onset of type 2 diabetes, and flagging the pattern can prompt useful screening.
Thrombosed Skin Tags and Other Look-Alikes
A thrombosed skin tag is one where a small blood clot has formed inside the growth, usually because of partial or intermittent twisting. These tags often turn a deep purple or dark blue before turning black, and they can be tender to the touch. The tenderness comes from the swelling of trapped blood inside a very small space. A thrombosed tag is not dangerous, but it can be more uncomfortable than a tag that simply twists and dies quickly. If the clot causes enough discomfort, a doctor can remove the tag with a quick snip or freeze it off.
Several other skin growths can darken and be mistaken for a dying skin tag. Seborrheic keratoses, which are waxy or rough-textured benign growths common in older adults, are a frequent source of confusion. They can be dark brown or black from the start and sometimes catch on clothing in ways that feel similar to a pedunculated skin tag. Cherry angiomas, small bright red spots caused by clusters of blood vessels, can also darken if they are traumatized. And as mentioned earlier, melanoma or other skin cancers can mimic the appearance of a benign skin growth, particularly in the early stages before they develop more obviously worrisome features.
The practical takeaway here is that the color change alone is not enough to identify what a growth is. A skin tag that turns black after clearly twisting or being treated is following a known, harmless script. A growth that was never clearly a skin tag and is changing color for no obvious reason deserves a professional opinion. Dermatologists can often distinguish these growths on sight, and when there is any ambiguity, a biopsy settles the question definitively.