SQ Drug Administration at Acupuncture Site GV20
I still remember the first time I came across the study by Pons and colleagues back in 2017. They were comparing dexmedetomidine given at the acupuncture point GV20 with the traditional intramuscular route. Honestly? I rolled my eyes. I even joked and called it “voodoo medicine.” Fast forward a few years to VMX in 2024, where a conversation with colleagues completely reignited my curiosity about this technique. When I got back to work, I pitched the idea to the surgical team and to my surprise, we decided to give it a try. And let me tell you, “eating my words” doesn’t even begin to cover it. The results spoke for themselves. Using GV20 has given us an easier, smoother way to restrain patients and administer drugs, all while keeping stress and anxiety to a minimum.
Where is the GV20 acupuncture site located?
GV20 stands for “governing vessel 20” and this acupuncture site is located on top of the head.
To find the GV20 location, I follow the ridges of the eyes to where they come together at the point of a “V” (red lines). The GV20 acupuncture point is located just caudal to the point of the “V” on the dorsal midline (sagittal crest) of the skull. Another way to find GV20 is to draw an imaginary line from the rostral ear base on both sides up to the dorsal midline, indicated with the blue dash line.
The black “X” on the skulls is the site of the GV20 injection in dogs.
How is the injection administered?
The drugs are administered subcutaneously (SQ) at or around the location of the GV20 acupuncture site. A 2024 study by Llido, et al. was the first to show a picture of the SQ injection at GV20. They angled the syringe and needle perpendicular to the head. I started doing the injection before this study was published and approached the injection at a different angle. I tent the skin with one hand and position the needle and syringe parallel to the head with the needle pointed in a cranial-caudal direction with the other hand. You can also point the needle in a caudal-cranial direction parallel to the head.
Can GV20 be used for cats?
Yes, yes it can! Finding the GV20 acupuncture site in a cat is straightforward. Pinch the skin between their ears (yellow X) and inject along midline of the skull. For restraint, I recommend wrapping a towel around the cat first, then the person restraining can put their arms on either side of the cat and use their hands to steady the head. Don’t put the cat in the towel and restrain the head until ready to give the SQ injection. Use a 25-gauge needle for the injection. Solash, et al (2025) just published the first cat study looking at using dexmedetomidine and methadone SQ at GV20.
What drugs can be used at this location?
The studies that are published have primarily looked at dexmedetomidine administered alone at this location. In dogs, there is evidence that atipamezole and hydromorphone also produce clinical efficacy at this location. In cats, there is evidence that dexmedetomidine and methadone work at this location. Anecdotally, I have used dexmedetomidine in combination with all the common opioids (e.g., hydromorphone, methadone, buprenorphine butorphanol) for premedication or sedation only procedures. I have also used Zenalpha® by itself or in combination with an opioid for procedural sedation in dogs. In a handful of cases, I have used acepromazine combined with an opioid in dogs that produced adequate sedation and analgesia prior to elective procedures but no clinical benefit over IM administration was observed. In cats, I have used dexmedetomidine combined with butorphanol, buprenorphine, methadone or hydromorphone. The clinical benefits mirror that of what we see in dogs.
What are the benefits of SQ at GV20 over IM administration?
The location of the injection is very easy to locate, and it is super easy to learn how to perform the injection. It requires minimal restraint of the patient. All that is needed is someone holding the head right behind the ears. In dogs, this location is advantageous for patients who resist restraint or who are apprehensive about their hindlimbs being touched. Although it seems counter intuitive, it works well for aggressive dogs if they can be muzzled first. Because the restraint is less and they can be easily distracted with gentle massage or scratching below their ears, most patients do not seem to react to this SQ injection the way that they would for an IM or IV injection. Perhaps there is less anticipation of what’s to come because they are enjoying the extra love scratches.
Now, here is the main benefit - When it comes to alpha-2 agonists, Pons, et al (2017) showed that there is a quicker onset time with a more profound sedative effect than when the same dosage of dexmedetomidine was administered IM. A study in 2021 by Scallan, et al. demonstrated that a reduced dosage of hydromorphone post-operatively administered SQ at GV20 provided comparable analgesia to a standard dosage of hydromorphone administered IM. However, this study had some major limitations that make interpretation of the data a bit questionable.
My clinical experience aligns with the Pons, et al (2017) study. The average onset time of dexmedetomidine with an opioid administered SQ at GV 20 in both dogs and cats is around 3 – 6 minutes, compared to an average of 15 – 20 minutes for an IM injection. At first, I was not decreasing the dosages of dexmedetomidine because I was concerned about duration of action. However, after seeing consistent and reliable sedation, I started decreasing the dosage of dexmedetomidine to be more in line with the IV dosages, 1 - 5 mcg/kg, and I am still seeing a great level of sedation with appropriate duration of effect. Although more research is needed in this area, it appears that we can utilize reduced dosages of several drugs while still seeing the expected effects at this GV20 location.
Pearls of Wisdom….
For dogs, stand off to the side of the patient rather than directly in front of them. Standing directly in front of a dog, especially when they do not know you, can make them feel uncomfortable and display nervous behavior.
If giving a large volume, like what is required for Zenalpha® (dogs only), I recommend using a 20-gauge needle. If you put too much pressure on the plunger while giving the injection, dogs seem to react more.
If the volume is smaller for a dog, then I use a 22-gauge needle. In cats, I use a 25-gauge needle.
Stay close to the skull for the injection when you tent the skin. If you place the needle high in the skin tent, then it is easy to stick the needle right through the skin. Re-sticking is often not possible because now the patient knows what is going to happen……it’s more than just love scratches.
Have the cap off the needle before pinching the skin and be ready to just give the injection. Pinch the skin, poke and give the injection. I do not tend to aspirate before administering the drug. The longer you are messing around the head, the more worried they tend to get.
Some cats will react to the initial stick so be prepared to just administer the drug immediately after you stick the needle in the skin. I do not recommend giving ketamine or tiletamine/zolazepam at this location because these drugs sting and the minimal restraint may not be adequate to prevent the cat launching off the table. The volume required for IM alfaxalone is large, so it makes me apprehensive to try using it at GV20, but we plan to give it a try at some point. Like dogs, a larger gauge needle will be needed to administer the volume, so excessive pressure is not put on the plunger during administration.
Where is the evidence?
Leriquier C, Freire M, Llido M, et al. 2023. Comparison of sedation with dexmedetomidine/atipamezole administered subcutaneously at GV20 acupuncture point with usual routes of administration in dogs presented for orthopaedic radiographs. J Small Anim Pract. Dec;64(12):759-768. doi: 10.1111/jsap.13668.
Llido M, Leriquier C, Juette T, et al. 2024. Comparison of sedation with dexmedetomidine administered subcutaneously at 2 different locations on the head in dogs. Can Vet J. Apr;65(4):351-358.
Pons A, Canfrán S, Benito J, et al. 2017. Effects of dexmedetomidine administered at acupuncture point GV20 compared to intramuscular route in dogs. J Small Anim Pract. Jan;58(1):23-28.
doi: 10.1111/jsap.12601.
Scallan EM, Eckman SL, Coursey CD, et al. 2021. The analgesic and sedative effects of GV20 pharmacopuncture with low-dose hydromorphone in healthy dogs undergoing ovariohysterectomy. Can Vet J. Oct;62(10):1104-1110.
Solash, B., Cheema, J. S., Freire, M., Benito, J., & Pang, D. S. (2025). Use of a novel subcutaneous injection site in the region of acupuncture point GV20 for premedicating cats before general anesthesia. The Canadian Veterinary Journal, 66(5), 537-545.
If you have not tried GV20………..what are you waiting for?
