Understanding the AG1 Side Effects: A Comprehensive Guide

November 27, 2025 •

5 min read

While AG1 is marketed as a comprehensive nutritional powerhouse, some users report experiencing unwanted side effects, most commonly digestive discomfort. Understanding the potential AG1 side effects is crucial for anyone considering this popular greens powder supplement.

Quick Summary

This guide details the potential downsides of AG1, including common digestive issues, risks associated with high vitamin levels, and potential interactions with certain medications. It also outlines who should exercise caution and steps to take to minimize discomfort.

Key Points

Digestive Distress: Bloating, gas, and diarrhea are common side effects, often caused by the high probiotic, prebiotic, and fiber content, especially when starting the supplement.
High Nutrient Levels: AG1 contains exceptionally high percentages of certain vitamins, which may be unnecessary if your diet is balanced and can pose risks in some cases.
Lack of Transparency: The use of proprietary blends makes it impossible to know the exact amounts of many ingredients, hindering assessment of efficacy and potential sensitivities.
Drug Interactions: The supplement can interfere with certain medications, including blood thinners, immunosuppressants, and some diabetes and blood pressure drugs.
Specific Contraindications: Pregnant or breastfeeding women, children, and individuals with autoimmune diseases or end-stage kidney disease should avoid AG1.
Minimize Risk: Starting with a smaller dose, taking it with food, and consulting a healthcare provider can help reduce the chances of experiencing negative side effects.

Common Digestive Side Effects

Many users of AG1 report experiencing gastrointestinal issues, particularly during their initial weeks of consumption. These effects are often attributed to the high concentration of probiotics, prebiotics, and other ingredients within the formula.

Bloating, Gas, and Diarrhea

Probiotics: AG1's 'Next Gen' formula contains a significant amount of probiotics (10 billion CFU) intended to support gut health. For individuals unaccustomed to such high quantities, this sudden introduction of new bacteria can disrupt the gut microbiome's balance, leading to increased gas and bloating as the body adjusts.
Prebiotic Fiber: The supplement includes prebiotic fibers like inulin, which feed beneficial gut bacteria. While beneficial, these fibers can cause fermentation in the colon, producing gas and leading to bloating in sensitive individuals. Some research also suggests inulin can cause issues for those with Irritable Bowel Syndrome (IBS).
High Fiber Content: A single scoop of AG1 provides 2 grams of dietary fiber. For those with low fiber intake, this sudden increase can cause temporary diarrhea as the digestive system adapts.

Stomach Upset and Nausea

Some users report general stomach upset or nausea, especially when consuming AG1 on an empty stomach. The supplement's complex blend of herbs and concentrated nutrients can be overwhelming for a sensitive stomach. Athletic Greens recommends starting with a half serving to allow your body to acclimate.

Concerns Regarding Nutrient Levels and Proprietary Blends

High Doses of Water-Soluble Vitamins

AG1 contains over 100% of the daily recommended value for several vitamins, including water-soluble ones like Vitamin C and B vitamins. For example, one scoop can provide 1100% of the daily value for biotin and 467% for vitamin C. While excess water-soluble vitamins are typically excreted via urine, this raises questions about the cost-effectiveness and necessity of such high doses, particularly for individuals already meeting their needs through diet. In some cases, chronic excessive intake of certain B vitamins like B6 has been linked to nerve damage.

Lack of Transparency in Proprietary Blends

AG1 uses proprietary blends, which means the exact amounts of many ingredients, such as herbs, adaptogens, and mushrooms, are not disclosed. This lack of transparency makes it impossible for consumers to know if they are receiving clinically effective doses of certain compounds or to accurately assess potential sensitivities. The 'secret formula' approach can be a significant drawback for health-conscious individuals who prefer full ingredient visibility.

Potential Drug Interactions and Contraindications

Due to its extensive list of ingredients, AG1 can pose risks for individuals on specific medications or with certain health conditions.

Interactions with Medications

Blood Thinners: The high Vitamin K content (as Menaquinone-7) can interfere with blood-thinning medications like Warfarin, reducing their effectiveness.
Immunosuppressants and Autoimmune Conditions: Ingredients like alfalfa and certain adaptogens may interact with immunosuppressants and are generally not recommended for people with specific autoimmune conditions like lupus.
Hormonal Birth Control: Some ingredients can potentially interfere with hormonal birth control.
Diabetes and Blood Pressure Medications: Interactions have been noted with some medications for diabetes and high blood pressure.

Populations Who Should Avoid AG1

Pregnant or Breastfeeding Women: The safety of many of AG1's ingredients for pregnant or nursing individuals is not established.
Children and Adolescents: The supplement is formulated for adults, and the high vitamin and mineral dosages are inappropriate for children under 18.
Individuals with Kidney Disease: Due to its potassium and phosphorus content, AG1 may not be suitable for people with end-stage kidney disease.

Comparison Table: Potential Risks of AG1


Area of Concern	High-Dose Vitamins	Proprietary Blends	Interactions/Contraindications
Details	Exceeds 100% DV for many water-soluble vitamins like B vitamins and C.	Specific quantities of many ingredients are not disclosed.	Potential interactions with medications (blood thinners, immunosuppressants) and specific health conditions.
Primary Risk	Potential for adverse effects from chronic, high-dose consumption (e.g., nerve damage). Cost-inefficiency as excess is excreted.	Inability to confirm therapeutic doses or identify potential triggers for sensitivities.	Serious health risks for at-risk groups and those on specific medications.
Actionable Step	Consult a doctor to assess necessity and safety, especially if taking other supplements.	Consider alternative products with transparent labeling if ingredient amounts are a concern.	Always discuss with a healthcare provider before use, especially if you have pre-existing conditions or take prescription drugs.

How to Minimize the Risk of Side Effects

If you choose to use AG1, several strategies can help reduce the likelihood of experiencing side effects:

Consult a Professional: The most important step is to talk with a healthcare provider or registered dietitian before starting. They can assess if AG1 is safe for your specific health profile and current medications.
Start with a Smaller Dose: As recommended by Athletic Greens, begin with a half scoop for the first few days to allow your digestive system to adapt to the probiotics and fiber.
Take with Food: To mitigate stomach upset and potentially improve the absorption of fat-soluble nutrients, consider drinking AG1 alongside or after a meal.
Stay Hydrated: Drinking plenty of water can help your body process the supplement and regulate digestive function.
Listen to Your Body: Pay close attention to how you feel. If side effects persist or worsen, it's best to stop taking the supplement and seek medical advice.

Conclusion: Weighing the Risks and Benefits

AG1 is a third-party tested product that packs a high density of micronutrients, probiotics, and other compounds into a single drink, which can be beneficial for filling nutritional gaps. However, the potential for digestive side effects, concerns over excessively high vitamin levels, and the non-transparent proprietary blends are valid considerations. Most importantly, AG1 is not suitable for certain populations and can interact with various medications. A "food-first" approach remains the gold standard for nutrition, and any supplement should be viewed as an adjunct, not a replacement. Before committing to this expensive supplement, it is crucial to carefully weigh the potential AG1 side effects against your individual health needs and consult with a healthcare professional to ensure it is a safe and appropriate choice for you. For more in-depth perspectives on greens powders, consider reviewing reputable nutrition sources, such as this article from Healthline: AG1 Review: A Dietitian and Health Editor's Take.

Frequently Asked Questions

Yes, AG1 can cause bloating and gas, particularly when you first start taking it. This is often due to the high dose of probiotics and the inclusion of prebiotic fibers like inulin, which can cause temporary digestive disruption as your gut adjusts.

AG1 should be avoided by pregnant or breastfeeding women, children under 18, and individuals with certain health conditions like autoimmune diseases (e.g., lupus) or end-stage kidney disease. It is also not recommended for those taking specific medications that may interact with its ingredients.

Yes, AG1 can interact with certain medications. Its Vitamin K content can affect blood thinners, and other ingredients can interfere with immunosuppressants, hormonal birth control, and drugs for diabetes and high blood pressure.

If you experience stomach upset, try taking a half scoop for the first few days to allow your body to adjust. You can also try drinking it with a meal, rather than on an empty stomach, to see if that helps.

The high percentages of water-soluble vitamins in AG1 are generally excreted if your body doesn't need them. However, it's wise to consult a healthcare provider before taking it to ensure safety, especially if you take other supplements, as excessive intake of some vitamins can cause issues.

AG1 does not disclose the exact quantities of many ingredients within its proprietary blends for reasons such as protecting its formula. This lack of transparency can be a concern for users who want to know specific doses or identify potential allergens.

Some anecdotal reports and concerns exist regarding liver health and supplements, but it is not a direct, common side effect of AG1 for healthy adults. Always consult your doctor before starting, especially if you have pre-existing liver conditions.