Semaglutide + B12
Good for: Those who want clinically proven weight loss support, combined with B12 to maintain energy and support metabolic health during treatment.
Semaglutide is a GLP-1 receptor agonist, a class of medication originally developed for type 2 diabetes that has demonstrated significant weight loss effects in clinical trials. Paired with vitamin B12 injections, this protocol supports both active weight reduction and the energy and metabolic health that make sustainable change possible.
Semaglutide mimics GLP-1, a hormone released after eating that signals fullness and reduces appetite. It also slows gastric emptying, which prolongs the sensation of satiety. Over time, this reduces caloric intake and drives meaningful weight loss. B12 supports the mitochondrial and neurological functions that sustain energy during active weight loss.
Every batch of compounded medication is third-party tested before it ships. All testing follows USP 797 and the relevant USP chapter for each test. Your provider continues to monitor your treatment, so quality doesn't stop at the pharmacy door.
Explained by our providers
How semaglutide and B12 work together
Semaglutide mimics GLP-1, a hormone your gut releases after eating that signals your brain to reduce appetite and slow gastric emptying. At the therapeutic dose used in semaglutide, that signal is strong enough to meaningfully change hunger and food intake over time. B12 is included to support energy and neurological health during treatment.
What to expect on semaglutide and B12
Appetite reduction is usually noticeable within the first 1 to 2 weeks, and meaningful weight loss builds over the following months and typically peaks between months 6 and 12. Nausea and GI discomfort are common during dose escalation and usually ease once you reach your maintenance dose, and your provider manages your titration pace based on how you're tolerating each step and stays involved throughout.
Pay for medicine, not marketing
Not all medications are created equal. Our prescriptions are compounded in the U.S. through our pharmacy partner with decades of experience and strict quality controls.
Ingredient quality
Sterility
Endotoxin
Potency
Our pharmacy partner is:
Inclusive care. Exclusively Haven.
- Born out of a doctor’s office, not a tech company
- Virtual check-ins with board-certified medical providers
- Pay for actual treatment, not subscription fees
Pricing breakdown
This medication may require lab testing that can be completed at a Haven Health or 3rd-party lab location. Your provider will determine what's necessary based on your care plan.
Common questions
Semaglutide has a well-established safety profile and is considered appropriate for many patients when prescribed and monitored by a licensed medical provider. However, it is not recommended for everyone. Your Haven provider will review your full health history to determine whether semaglutide is a safe and appropriate option for you. Gastrointestinal side effects (see below) are common but usually mild.
Semaglutide + B12 is self-administered via weekly subcutaneous injection, typically into the abdomen, thigh, or upper arm. Your provider starts you at a low dose and escalates gradually over several weeks to minimize GI side effects and give your body time to adjust.
Most patients experience a meaningful reduction in appetite within the first 1 to 2 weeks. Weight loss typically becomes apparent by weeks 8 to 12 and continues to build over months. GI side effects such as nausea or mild upset are most common during the titration phase and generally improve. Energy may fluctuate early as your body adapts to reduced caloric intake, which is where B12 support helps.
The most common side effects are GI-related: nausea, constipation, or mild diarrhea, particularly during dose increases. These tend to diminish as your dose stabilizes. Less common effects include fatigue, mild headache, or injection site reactions. Serious side effects are rare but include pancreatitis and gallbladder issues; your provider will review the full risk profile with you before starting.
Semaglutide has been studied extensively in the STEP clinical trial program, which demonstrated average weight loss of approximately 15% of body weight over 68 weeks at the 2.4 mg dose. The GLP-1 mechanism is supported by decades of diabetes and metabolic research.
Sources:
- Once-Weekly Semaglutide in Adults with Overweight or Obesity. DOI: 10.1056/NEJMoa2032183
- Semaglutide therapy for metabolic dysfunction–associated steatohepatitis: November 2025 updates to AASLD Practice Guidance. DOI: 10.1097/HEP.0000000000001608
