The Core 4: The Foundation Every GLP-1 Journey Is Built On
Eating less shouldn't mean getting less of what your body needs. These four supplements cover the gaps, in every phase.
Key takeaways
One doesn’t have a single nutritional deficit, as eating less leaves you with small gaps across multiple nutrients, which is why there are four products as the foundation rather than one.
The Core 4: a high-quality multivitamin, vitamin D3 with K2, a synbiotic, and magnesium.
Leading medical and nutrition organizations have identified key nutrient priorities during GLP-1 therapy as an ongoing concern, not just an early-months one.
For most people, the Core 4 is the whole supplement plan. Everything else is added only when there's a specific reason.
Not sure which phase you're in, or what to add on top of the foundation?
The Most Common Question We Hear, and Why It's the Wrong One First
One of the most common questions we hear is: "What supplements should I take while I'm on Ozempic or Wegovy?"
It's an important question. But it's not the first one.
It’s not that eating less usually leads to a single nutrient deficiency. It results in multiple minor nutrient deficiencies at once.
It’s not one supplement that’s the answer. It’s the base.
The GLP-1 drugs work by cutting down on how much you eat. That’s how they can help you lose weight, and that’s also what causes those gaps: less protein, vitamins and minerals, fluids, and electrolytes get to a body that still requires all of them. Many people don’t have any symptoms as they occur.
We didn’t find any of this to be shocking. Medications which interfere with nutrient absorption and utilization have been in pharmacy stores for years and addressing this sort of nutrient deficiency has been something we’ve done for a very long time. GLP-1’s are just another example, perhaps the largest example yet.
The medication changes how much you eat. It doesn't change what your body still needs.
Think of the Core 4 vitamins to take while on Ozempic as the nutritional foundation that stays with you from your first injection through long-term maintenance, and even as you transition off medication.
Nutrient Depletion Isn't New to Us
Long before GLP-1s were available, we were already focused on making sure our clients get back the things that the medications are silently robbing them of. More than 60 years of watching how medications and nutrients affect each other gives us a strong basis for the Core 4 based on both scientific evidence and real world clinical experience. And it’s why we always start with less, not more.
Your Nutritional Foundation: Meet the Core 4
1. High-quality multivitamin
The broadest net you could possibly throw is a multivitamin.
Best for:
Broad nutrient coverage
Everyday energy
Immune function
The wide-ranging gaps that open when you eat less
Why it matters. It covers the vitamins and minerals your body draws on every day for energy, immune function, tissue repair, and metabolism, rather than leaving you to guess which specific gap opened up.
What to look for. Active and bioavailable forms of vitamins and minerals; methylated B vitamins and chelated minerals rather than cheap generic versions. A vitamin designed for women should provide iron up until menopause as well as extra support for bones.
What we recommend. Our Pathway Essentials Coenzymated Multivitamins use B vitamins in their active, ready-to-use forms, no conversion required. Three options, so you can choose the one that fits:
→ Coenzymated Advanced Men's Multi
→ Coenzymated Pro Advanced Women's Multi, accounts for iron needs before menopause
→ Coenzymated Once Daily Multi, No Iron, for anyone who doesn't need supplemental iron, or takes it separately
2. Vitamin D3 with K2
Best for:
Bone health
Immune support
Muscle function
Steady support for long-term GLP-1 use
Why it matters. The link between Ozempic and vitamin D matters because insufficiency is already widespread before treatment begins. Weight loss shifts how your bones remodel, a process that depends on steady vitamin D. K2 works alongside D3 to help direct calcium where it's needed most.
Look for D3 (cholecalciferol) rather than D2, combined with K2. You should know what your level is. If you have it tested, use that information to determine your dose.
What we recommend. Pathway Essentials Vitamin D3 + K2 pairs cholecalciferol with vita MK-7, the well-researched MK-7 form of K2. It comes in two strengths so you can match your intake to your needs, and it's the one Core 4 supplement where bloodwork, not guesswork, should drive the dose. Our team can help you interpret yours.
3. Synbiotic
Best for:
Digestion
Gut comfort
Microbiome balance
The gut changes that start in week one
Why it matters. GLP-1 medications shift how your gut moves from the earliest weeks, and those changes continue throughout treatment. A comprehensive synbiotic, probiotics with prebiotic and postbiotic support, helps maintain gut barrier health and a balanced microbiome, which support healthy digestion and nutrient absorption.
What to look for: Clinically-studied ingredients, multiple strains with significant CFU count, along with a prebiotic fiber to feed them.
What we recommend. Humanized Nutrition Pro Advanced Synbiotic is built for exactly this job. It delivers all three layers of gut support in one daily capsule: clinically studied probiotic strains, the prebiotic fiber that feeds them, and the postbiotic compounds that support your gut barrier.
4. Magnesium
Best for:
Sleep
Energy
Muscle function
Stress resilience
Why it matters. Magnesium supports hundreds of essential processes throughout the body, and it's one of the nutrients most likely to fall short as food intake decreases. It supports muscle function, energy, sleep quality, stress resilience, and regularity, all of which come under more pressure during treatment.
What to look for. Magnesium glycinate is usually the most easily tolerated form, and most helpful for sleep and stress resistance. Magnesium oxide is widely available, and cheap, but not very well absorbed.
What we recommend. Pathway Essentials Magnesium Glycinate 400 mg, gentle on a stomach that's already digesting slowly, well absorbed, and the form best suited to sleep and stress support, which is why we suggest taking it in the evening. Available in two sizes, depending on whether you'd rather restock often or stock up.
How to Take Your Core 4
Supplement |
When to take it |
On a GLP-1, this matters because |
Multivitamin |
Food: improves absorption and reduces stomach upset, which is more important if you’re not absorbing nutrients quickly. |
Covers the wide range of nutrient deficiencies you face when you eat less in general |
Vitamin D3 + K2 |
With your largest meal, it's fat-soluble, so some fat helps it absorb |
Supports the bone remodeling that rapid weight loss speeds up, and levels are often low before you even start |
Synbiotic |
The benefits of use accumulate over time and are most beneficial when you don't miss a day, so not worrying about the exact time of day is probably more important than getting it right. |
Supports the gut, which shifts in the first few weeks of being on a GLP-1 and plays a role in digestion and nutrient uptake. |
Magnesium glycinate |
In the evening 30-60 mins before bedtime, the glycinate form supports relaxation. So this form works well at night. |
It replaces one of the first minerals to be depleted with insufficient intake and promotes sleep and regularity, which can get more difficult over time. |
Why We Chose These Four
Leading medical and nutrition organizations have identified key nutrient priorities during GLP-1 therapy as an ongoing concern, not just an early-months one. These are the same gaps the Core 4 is designed to fill.
That does not mean everyone on a GLP-1 will be deficient. It means that the odds of being deficient rise significantly when you’re eating significantly less and universal, blanket coverage is the right answer for a known problem. The advisory tells us nothing we do not already know. We have been doing the work for decades to help people replace what they are missing due to their medications.
Start Here. For Most People, This Is All You Need.
The Core 4 addresses the deficiencies that occur for virtually everyone taking a GLP-1. It’s not just the first 4 items on a much longer list. It’s the entire plan.
The order of importance is: food first. The Core 4 supplements are to fill in any gaps that food doesn't. And then if there's a reason to take additional things such as a particular stage, need, or symptom, then add that in.
We'd rather you take four things well than ten things halfway. So if you're wondering whether you need more than the foundation, there's an easy way to find out. Take the assessment, or have a quick chat with our team of nutrition experts.
The other three give you some decisions to make: what’s the best multivitamin for you, how much vitamin D do you need, what dose of magnesium should you stockpile? The base layer is common to all, but the ingredients filling it out aren’t. Why not just build your whole base layer in one place?
What Sits on Top of the Foundation
The Core 4 is what doesn’t change. Beyond that, some phases need just one or two extra items, but only if those aren’t already being provided by the food and the core. No one person needs all of these, but you’ll want to include the two that apply to your phase (if any are needed).
The Core 4 remains unchanged. For some phases, you'll have an extra one or two supplements to consider, but only if food alone isn't meeting that need. Only take what's required for your phase.
Phase |
Possible Phase-Specific Support |
Phase 1 · Just Starting |
Digestive support + active B12 |
Phase 2 · Actively Losing |
Creatine monohydrate + collagen peptides |
Phase 3 · Plateau |
Stress support + therapeutic-dose omega-3 |
Phase 4 · Maintenance |
Creatine monohydrate + therapeutic-dose omega-3 |
Phase 5 · Transitioning Off |
Blood sugar support + appetite control |
The foundation stays the same. The support evolves with your body.
Not Sure Where to Start?
Regardless of what stage you are in, the base will be the same, and it is the first place to start.
Still not sure if you need more than the Core 4? Get a free GLP-1 Nutrition Assessment that identifies your phase in about two minutes. Your results will include your nutrition goals for protein, fiber, and hydration, priority add-ons if you need them, lifestyle habits worth prioritizing, and what to focus on today.
Get Your Personalized Phase Report ►
If you want a program that’s based purely on you, we have our Clinical Nutrition Program. It involves personal consultations, complete review of health histories and lab work, and customized treatment programs.
Book a Nutrition Consultation ►
GLP-1 medications can be powerful. But eating less shouldn't mean getting less of what your body needs.
Start with your foundation. Then follow your phase.
Frequently Asked Questions
What supplements should not be taken with Ozempic?
The short answer is: nothing in the Core 4 needs to be avoided on a GLP-1. What we do steer people away from are the transdermal or oral "natural GLP-1" dietary supplements marketed as boosters. A 2026 pharmacology analysis flagged these as unlawful and potentially risky. Real support comes from covering nutrient gaps, not from products claiming to mimic your medication.
Does Ozempic cause vitamin deficiency?
It is associated with an increased risk, though, right? In a real-world study of over 461,000 adults taking GLP-1s, nearly 1 in 5 developed a nutrient deficiency in the first year. The most common was vitamin D, followed by iron and B vitamins. And many patients were completely asymptomatic during the development of these deficiencies. So, that is why we need broad, steady coverage as the baseline.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. The information in this article is educational and is not a substitute for advice from your healthcare provider.
References
- NIH Office of Dietary Supplements, Vitamin D Fact Sheet for Health Professionals
- NIH Office of Dietary Supplements, Vitamin K Fact Sheet for Health Professionals
- NIH Office of Dietary Supplements, Magnesium Fact Sheet for Health Professionals
- NIH Office of Dietary Supplements, Multivitamin/Mineral Supplements Fact Sheet
- Current Developments in Nutrition, Plant-Based Nutrition During GLP-1 Therapy
- NIH Office of Dietary Supplements, Vitamin B12 Fact Sheet for Health Professionals
- Transdermal "Natural GLP-1" Dietary Supplements Violate Law and Place Patients at Risk (Ann Pharmacother, 2026)
- MedlinePlus, Semaglutide Injection
- Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society (Obesity, 2025)
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