Vitamin D3
Cholecalciferol is converted in the liver and kidney to calcitriol, the active hormone regulating calcium absorption, bone metabolism, and immune signaling.
Medically reviewed by Dr. Jonathan Snipes, MD. Last reviewed May 6, 2026.
What It Is
An injectable form of vitamin D3 (cholecalciferol) at 50,000 IU/mL. Self-administered intramuscular, typically dosed weekly to monthly per labs.
How It Works
Injected D3 is hydroxylated to 25-hydroxyvitamin D and then to active calcitriol, supporting calcium and phosphate homeostasis, bone mineralization, and immune function. Injection helps patients with malabsorption or persistent deficiency on oral D3.
Who It's For
Patients with documented vitamin D deficiency or malabsorption who have not responded to oral supplementation. Dosing guided by 25-OH vitamin D labs.
Who Should Avoid It
Hypercalcemia, hypervitaminosis D, or sarcoidosis-related calcium dysregulation. Dose by lab values; do not stack multiple high-dose D sources. Flag for provider review.
Protocol & Pricing
OBP Pharmacy Price
$55/30ml
You pay pharmacy price. No markup.
Starting Dose
50,000 IU (1mL) once monthly
Form
Injectable vial (30mL, 50,000 IU/mL cholecalciferol)
Dosing Protocol
50,000 IU (1mL at 50,000 IU/mL) intramuscular once monthly, or per provider based on 25-OH vitamin D labs. Single 30mL vial ($55). Do not exceed provider-directed dosing.
Beyond Use Date
90 Days from compounding (USP <797>)
Use within this window from the date your vial is compounded. BUD is set per USP <797> sterile compounding standards and printed on every label.
Stacking Guide
Stacks Well With
Related Peptides
How to get Vitamin D3 prescribed online
Vitamin D3 is available by prescription through a licensed telehealth visit and dispensed for human use by a named 503A pharmacy. That is what separates it from research-use-only vials sold without a prescription. There is no subscription and no membership, just a one-time visit fee.
- 1
Complete a $39 medical visit. Answer a short intake about your health history and your goals for Vitamin D3. The $39 fee is the only charge RxPepsDirect collects, paid once, not a recurring subscription.
- 2
A licensed provider reviews it. A US-licensed nurse practitioner or physician reviews your intake and, if Vitamin D3 is appropriate for you, writes a patient-specific prescription. The starting dose is typically 50,000 IU (1mL) once monthly.
- 3
The pharmacy compounds and ships it. Optimal Balance Pharmacy, a 503A pharmacy in Texas, compounds Vitamin D3 and ships it pre-reconstituted by FedEx overnight in a reusable cooled case. Your fill is Injectable vial (30mL, 50,000 IU/mL cholecalciferol), and you pay the pharmacy $55/30ml at wholesale, with no clinic markup, plus a $15 flat FedEx overnight shipping fee charged by the pharmacy.
RxPepsDirect prescribes Vitamin D3 in the 28 states its medical team is licensed in. Start a $39 visit or browse the full Vitamins & Injectables range.
Common questions about Vitamin D3
- What is Vitamin D3?
- An injectable form of vitamin D3 (cholecalciferol) at 50,000 IU/mL. Self-administered intramuscular, typically dosed weekly to monthly per labs.
- How does Vitamin D3 work?
- Injected D3 is hydroxylated to 25-hydroxyvitamin D and then to active calcitriol, supporting calcium and phosphate homeostasis, bone mineralization, and immune function. Injection helps patients with malabsorption or persistent deficiency on oral D3.
- Who is Vitamin D3 for?
- Patients with documented vitamin D deficiency or malabsorption who have not responded to oral supplementation. Dosing guided by 25-OH vitamin D labs.
- How much does Vitamin D3 cost?
- Vitamin D3 costs $55/30ml from Optimal Balance Pharmacy at wholesale, with a flat $39 medical visit fee from RxPepsDirect. The form is Injectable vial (30mL, 50,000 IU/mL cholecalciferol).
- What is the Beyond Use Date for Vitamin D3?
- 90 Days from compounding (USP <797>) BUDs are assigned per USP <797> sterile compounding standards and printed on every vial label.