Dry Cupping Therapy for Neck Pain: Monitoring for Adverse Effects

Cupping therapy is a complementary medicine technique that uses negative pressure (vacuum) under the skin to relieve musculoskeletal pain. Despite its growing popularity and millennia-old use, the practice still faces significant challenges related to a lack of standardization and adequate monitoring of adverse effects. This prospective, double-blind study had as its main objective to develop a reproducible device for objective pressure measurement during cupping therapy and to systematically investigate adverse effects reported after applications at different pressure intensities on the neck. The researchers developed an adaptation of a commercial cupping kit, incorporating an analog vacuum gauge between the suction gun and the cups.

This modification allows precise and standardized measurement of applied pressure, addressing one of the main methodological limitations identified in the scientific literature on cupping therapy. The study included 30 women aged 18 to 59 years, randomized into two groups: one received dry cupping at a pressure of -150 mmHg and the other at -300 mmHg. The protocol consisted of applying three cups for 5 minutes at the points Jianjing (GB-21) bilateral and Dazhui (GV-14), followed by systematic monitoring through a structured questionnaire during application, immediately afterward, and at 24 and 72 hours. The results revealed significant differences between the groups regarding the incidence and duration of adverse effects.

The high-pressure group (-300 mmHg) presented a mean of 1.9 adverse effects per participant, compared with 1.083 in the low-pressure group (-150 mmHg), with a statistically significant difference (p = 0.0007). During application, both groups reported mainly painful sensations, with neuropathic effects such as tingling and itching being more frequent in the high-pressure group. At immediate reassessment, an overall reduction in adverse effects was observed, but with predominance of inflammatory effects, especially ecchymoses in the higher-pressure group. The 24-hour follow-up revealed the emergence of systemic symptoms such as headache and muscle tension, more pronounced in the high-pressure group.

At 72 hours, adverse effects persisted mainly in the high-pressure group, with 8 participants still reporting symptoms versus only 3 in the low-pressure group. The ecchymoses in the low-pressure group resolved completely within 72 hours, while 5 participants in the high-pressure group still presented this effect. The developed device proved effective for standardized pressure measurement throughout the research period, offering an accessible and replicable solution for future studies. The adaptation was low-cost and easily reproducible, although it requires attention to the specifications of each cup manufacturer.

The clinical implications of this study are important for safe cupping practice. The results demonstrate that even relatively low pressures can cause adverse effects, and that there is a direct correlation between the intensity of applied pressure and the incidence/duration of unwanted effects. This underscores the need for adequate clinical knowledge and well-established safety protocols. The adverse effects observed were characterized as minor and of low severity, including localized pain, tingling, ecchymoses, and occasionally headache and muscle tension.

No serious adverse effects reported in the literature were observed, which generally result from inadequate application or lack of necessary precautions. The study presents some important limitations: it used only a single application, was limited to female participants to reduce hormonal variability, and the developed equipment does not allow continuous pressure monitoring. Future studies should include male participants, investigate multi-session protocols, and develop devices with continuous pressure monitoring.