Capsule cigarettes allow users to crush liquid-filled capsules to release flavors into cigarettes' filters. New devices are emerging across the globe that allow people who smoke to circumvent tobacco flavor restrictions via injectable capsules. This study examined TikTok videos marketing flavored capsule injector devices. TikTok videos (n = 832) posted worldwide between July 6, 2021, and December 28, 2023, that used hashtags #injectorflavor, #flavourclickball, #flavorball, and #injectorballcigarette were collected using a TikTok application programing interface. A codebook was developed using a systematic iterative approach, identifying six codes: flavor capsules, promotes flavors (i.e., fruit, mint or menthol flavors, non-alcoholic drinks, alcoholic drinks), demonstrates how to use or refill large injector devices, demonstrates how to use small convenient devices, includes music (any or English-language). Two independent coders annotated all videos. Overall, 88.3% (n=735) of the videos displayed flavor capsules and had been viewed more than 72 million times. Half (51.6%) of the videos demonstrated how to use large box-shaped devices to inject capsules into the filter of a cigarette, and 15.0% of the videos showed how to do this with smaller, more convenient devices. Flavors including fruit (35.5%), menthol/mint (27.8%), non-alcoholic drinks (21.9%), and alcoholic drinks (11.6%) were used to promote these capsules. Most videos (85.6%) were uploaded by sellers on "TikTok shop." TikTok accounts are promoting injectable capsule devices that circumvent flavored tobacco sales restrictions. Policy makers, tobacco control advocates, and public health practitioners should be aware of such marketing to inform regulation and develop prevention strategies. Our findings identified an emerging product that can encourage circumvention of flavor restriction policies. Regulators, policy makers, public health practitioners, researchers, and advocates should be aware of such products to inform regulation and develop prevention strategies. Given the potential for these products to reduce the intended effects of flavored tobacco sales restrictions, policy makers must be poised to address materials that consumers use to create their own flavored tobacco products, including flavor capsules designed to be inserted into cigarettes.