Vitamin B12 shots are marketed at med spas as quick energy boosts, but health experts report that extra doses provide no benefit for people who already have adequate levels of the nutrient. While the injections are generally safe, they are often unnecessary and expensive for individuals without a deficiency.
Social media feeds feature med spa owners and employees endorsing vitamin B12 injections as a fast remedy for fatigue during busy weeks. These businesses often claim that clients feel an energy lift within a day or two and recommend scheduling repeat visits every few weeks.
What Vitamin B12 Does for the Body
Vitamin B12 is found naturally in animal foods like meat, fish, eggs, and dairy, and it is added to some breakfast cereals and nutritional yeasts. It helps your body make red blood cells and DNA, and it keeps your nerves working properly. This nutrient also assists in metabolizing food into usable energy, which explains why it is widely known as an energy-enhancing substance.
When people lack sufficient B12, they can develop anemia, memory problems, depression, and fatigue, according to Andrea Dean, a hematologist at Loyola University medical center in Chicago. If levels drop seriously low, patients can also experience numbness and tingling in their hands and feet.
Why Some People Run Low on the Nutrient
Eating foods rich in vitamin B12 does not always guarantee adequate levels because the stomach must produce sufficient acid and a protein called intrinsic factor to absorb the vitamin. When people develop deficiencies despite eating a balanced diet, it is often due to conditions that reduce stomach acid, such as gastritis, or pernicious anemia, an autoimmune condition where the stomach stops making intrinsic factor.
Roughly 4% of individuals in the United States experience low B12 concentrations, with this shortage appearing more frequently among older individuals aged 60 and older. Other risk factors include weight loss or stomach surgery, digestive conditions like celiac or Crohn’s disease, and heavy alcohol use.
Long-term use of the diabetes drug metformin or acid-reducing medications can also lower B12 levels, while vegans and some vegetarians face higher risks unless they eat fortified foods or take supplements.
Financial Profits Versus Medical Reality
Treating a deficiency can restore energy for people experiencing fatigue or mental slowing due to low B12, but getting extra doses when levels are already adequate will not make anyone less worn out or improve athletic performance. Dean compared the situation to filling a car: if the gas tank is already full, adding more gas will not make the vehicle go faster.
Some people who feel more energetic after an injection may be experiencing a placebo effect, with Dean noting that part of the response is mental. For med spa owners, the injections also offer a financial incentive, as the shots cost a typical US spa less than $1 each to buy and are sold to consumers for $25 to $75 per dose.
When to Test and How to Treat Deficiency
Fatigue has many possible causes, including poor sleep, low thyroid hormone, and low iron, meaning it is not always related to B12, according to Dean. A primary care doctor can order a simple blood test, or patients can order one online through commercial labs in many US states and the UK.
Interpreting results can be complex because a person can still be deficient even if results appear normal, with most labs setting the low threshold at less than 200 or 250 pg/mL, while Dean treats anyone below 400 pg/mL.
For borderline cases, doctors can order additional blood tests called methylmalonic acid and homocysteine to confirm a deficiency.
Treatment depends on the underlying cause, and options include oral pills or injections delivered into a muscle or under the skin to bypass the gut entirely.
Shots are necessary for severe deficiencies or nerve symptoms, but high doses of oral B12 work just as well for many others while costing less. When patients present with nerve symptoms, Dean stated, doctors do not play around.
Common Questions About Vitamin B12 Testing and Treatment
Who needs a vitamin B12 injection instead of a pill?
Injections are recommended for people with severe deficiencies, nerve symptoms, or conditions like pernicious anemia that prevent normal absorption in the gut.
How much do vitamin B12 shots cost at med spas?
Med spas typically purchase the ingredients for less than $1 per shot and sell them to consumers for prices ranging between $25 and $75.
What blood levels indicate a B12 deficiency?
Most laboratories flag levels below 200 or 250 pg/mL as low, though some specialists begin treatment for patients with symptoms when levels fall below 400 pg/mL.