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Methylcobalamin B12Active B12, 5 mg/mL injection
$39 $19.50 50% off
first mo.as low as · choose 3 or 12 months
How a B12 injection gets past your gut.
Prescription methylcobalamin B12 · 5 mg/mL
As low as $39 $19.50 50% off for the first month
Choose 3 or 12 months
Running again.
Verified B12 customer
Active formMethylcobalamin, not cyano
Skips the gutInjected, not swallowed
5 mg/mLIn a 10 mL vial
The questions people actually ask
Four questions about B12 injections.
What a tablet has to get through, which form of B12 you are given, what B12 does once it is in you, and who makes the vial.
The absorption chain
Why does a tablet lose so much on the way in?
- Swallow
A tablet starts in the stomach, not the bloodstream.
- Stomach acid
Acid and pepsin have to free B12 from the food or the tablet matrix.
- Intrinsic factor
A stomach protein has to bind the B12 for it to be carried onward.
- The ileum
The last stretch of small intestine has to absorb the bound complex.
- Bloodstream
Only what survives all four steps ever reaches your cells.
The injectionStraight to the tissue
The dose is placed under the skin. It never enters the chain above, so none of those steps gets a say in how much of it lands.
Absorption steps described in the NIH Office of Dietary Supplements Vitamin B12 Fact Sheet for Health Professionals.
Two forms, one label
Methylcobalamin or cyanocobalamin?
- What it is
- A metabolically active form of vitamin B12
- A synthetic form that carries a cyanide group
- Conversion needed
- None. It is already in an active form
- Yes. The body has to convert it before use
- Where you find it
- Rebody's prescription injection, 5 mg/mL
- Most over-the-counter B12 tablets and drops
- How it reaches you
- Injected into the tissue, so absorption is not the gate
- Swallowed, then run through the full absorption chain
- Who sets the dose
- A licensed provider, from your history and prior results
- Whatever the bottle on the shelf prints
What B12 does all day
Three jobs your body cannot skip.
Your body cannot make B12. Every one of these jobs waits on what you take in, and the first one you feel is energy.
- It runs the energy line
B12 is a cofactor in the reactions that convert food into usable cellular energy. Short on B12, that line slows and the fatigue is real, not imagined.
- It builds red blood cells
Normal red blood cell formation and DNA synthesis both depend on B12. Those cells carry the oxygen that everything from a staircase to a long ride runs on.
- It protects your nerves
B12 supports the myelin around nerve cells and normal neurological function, which is the difference between clear thinking and fog.
Roles described in the NIH Office of Dietary Supplements Vitamin B12 Fact Sheet for Health Professionals.
Where it is made
Who makes the vial, and to whose prescription?
Compounded by a licensed 503A pharmacy
Your vial is compounded in the United States against a prescription written for you, which is why the label carries your name, your active, and your strength. A shelf bottle answers to none of that.
- Form
- Methylcobalamin
- Strength
- 5 mg/mL
- Vial
- 10 mL
- Supply
- 90 days
Inside the price
Five things you never pay extra for.
As low as $39 $19.50 50% off for the first month. Choose 3 or 12 monthsEverything below is inside those numbers.
No separate consult fee
The online provider review is inside the package price.
Refunded if it is declined
If a provider does not prescribe B12 for you, you get your money back.
FSA and HSA cards accepted
Pay with your benefits card at checkout, the same as any other card.
Pause or cancel any time
Change or stop your plan before the next shipment bills.
B12 results
What B12 customers say.
Daycare pickup is easier
“My B12 was low and I felt terrible every afternoon by the time I picked up my daughter. Four weeks into the shots, I am getting through work and daycare pickup without crashing on the couch. My Rebody clinician explained the lab results clearly, and the shipment included all the supplies.”
More energy after work
“My labs showed low B12 and the clinician recommended weekly shots. After a few weeks I have more energy after work and am not going directly to the couch every day. Rebody included everything I needed with the first shipment.”
Running again
“I eat mostly plant based, so low B12 was not a surprise. What surprised me was how much better I felt after starting the injections. Seven weeks in, I am running before work a few times a week instead of turning around after the first mile.”
How Rebody works
From question to first dose.
- 01
Tell us about your afternoons
A few minutes online about your fatigue, diet, medications, health history, and any prior B12 result.
- 02
A licensed provider reads it
A U.S. provider sets your dose and your directions. No waiting room and no referral.
- 03
A licensed pharmacy fills it
A U.S. compounding pharmacy prepares your 10 mL vial.
- 04
Three months land on your doorstep
Your vial ships free in discreet packaging, with directions and dosing on the pharmacy label.
How B12 works
The science questions people ask.
Do I need a blood test first?
Serum B12 is the common first test, and methylmalonic acid is a more sensitive confirmatory marker when a serum result is borderline. Share any prior result in your visit. Your provider decides what is needed in your case.
Will B12 give me energy if my level is already normal?
Extra B12 is not a general stimulant when your B12 status is already adequate. Low B12 can cause hematologic and neurologic problems, and fatigue is a useful signal in context, but fatigue alone does not identify a shortfall. Your level, your diet, your medications, and your absorption decide it, which is what the provider review is for.
Do I need a prescription?
Yes. A licensed U.S. provider reviews your online health visit, and a licensed U.S. compounding pharmacy fills and ships the medication when it is prescribed.
Safety and prescribing
Important safety information.
Tell your provider about every medication and supplement you take, your allergies, any prior B12 result, and your complete health history. Injection-site pain, redness, itching, or swelling can occur.
Seek urgent care for signs of a serious allergic reaction, including trouble breathing, facial swelling, severe dizziness, or fainting. Do not share your vial or your injection supplies with anyone.
Compounded medications are not FDA-approved or evaluated for safety, efficacy, or quality by the FDA. Prescription required. Not available in all states. Results vary.
Methylcobalamin B12 at home
Active B12, straight to the tissue.
Active B12, injected as prescribed. Choose 3 or 12 months. Free shipping, and the provider review included. FSA and HSA cards accepted, and a full refund if a provider does not prescribe.
Choose 3 or 12 months Medication, provider review, and shipping are inside the price.