Issue 19: Is AG1 Worth Trying?

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Welcome to Weekly.health’s 19th issue. Every week, we explore cutting-edge research, actionable advice, and science-backed nutrition insights to help you live longer and healthier.

Our aim is to help you live another 10 healthy years and cut your risk of age-related disease.

🗒️ In This Issue:

• 📚 Books We’re Reading Right Now

• 📈 Research Digest: What’s new in nutrition science

• 💊 Supplement Deep Dive: AG1

• 🛍️ Things You Might Like

• ❤️ Support Weekly.health: Help us keep the research flowing

• 📘 Glossary of Terms: Definitions for technical terms in this issue

📚 Books We’re Reading Right Now

📈 Research Digest: What’s New in Nutrition Science

Here’s the best of recent nutrition research:

🍇 Berries can benefit your gut if you eat enough
A daily dose of anthocyanins (320 mg, equal to ~1 cup or 100-150g of blueberries or blackcurrants) tweaked gut bacteria in older adults, especially those who were older, obese, or had an unhealthy gut. After 24 weeks, they showed more “good” bacteria and fewer inflammatory ones. No memory boost was seen, but gut health improved. Aim for a cup of dark berries a day to get the effect. (source)
Takeaway: Eat a variety of dark-skinned berries like blueberries, blackberries, blackcurrants and similar. But, dosage is key - consume 1.5 handfuls / 1 cup / 100-150g daily to get enough of the beneficial anthocyanins.

🍬 Swap sugar for sweeteners to keep weight off
In a 1-year RCT of 341 adults, replacing sugar with low/no-calorie sweeteners after a 2-month diet maintained an extra 1.6 kg weight loss versus a low-sugar diet without them. The sweetener group cut ~12 g/day more sugar and showed gut microbes that make helpful short-chain fatty acids. Watch for bloating or loose stools. (source)
Takeaway: While sweeteners are often vilified they do reduce your calorie intake, and this is likely to result in larger weight-loss. Replace added sugar in your diet with sweeteners to reduce calories.

🥗 Cutting back on ultra-processed foods (UPFs) can reshape your gut health
In this 6-month clinical trial, people with obesity who limited UPFs to just 5% of their diet saw increases in beneficial gut bacteria like Faecalibacterium - linked to reduced inflammation - and lost body fat and waist size. Even with the same calorie restriction, those avoiding UPFs enjoyed a healthier gut ecosystem and better metabolic outcomes. (source)
Takeaway: Many ultra-processed foods are advertised as being low-calorie and great for weight-loss, but emerging research suggests they promote overeating, and in this research, poorer gut bacteria. If you are cutting calories for weight-loss, eat a whole-food diet and cook your meals from scratch to minimise your intake of UPFs.

💊 Supplement Deep Dive: AG1

1-minute verdict

Try (with caveats) — AG1 is a convenient “all-in-one” daily greens powder that functions like a multivitamin/mineral plus fibre, phytonutrients and a 5-strain probiotic. It includes 75 ingredients, with many from various plants, fruits, and vegetables, to make it easy to increase the variety in your diet. Human trials (including an RCT) suggest it can raise certain nutrient biomarkers and enrich aspects of the gut microbiome, but it’s not a substitute for a balanced diet and won’t extend lifespan.

Outcomes that matter:

• Increases selected nutrient biomarkers (e.g., folate, vitamin C) over weeks.

• Enriches beneficial gut bacteria and may improve digestive symptom scores (small effect, short duration studies).

• Rapid absorption of some vitamins/minerals in an acute bioavailability study (hours).

Time to benefit: Acute absorption in hours; microbiome and biomarker shifts typically 2–12 weeks.

Who should avoid / adjust: Pregnancy or trying to conceive (mind total vitamin A from all sources); anyone having blood tests that can be affected by biotin; those already on high-dose multivitamins or separate B-complex. Consult your doctor if on anticoagulants or with GI conditions.

Upper limit: Stay within EFSA tolerable upper intake levels (e.g., vitamin A 3,000 µg retinol equivalents/day; folic acid 1,000 µg/day; zinc 25 mg/day; selenium 255 µg/day) from all sources. Don’t stack AG1 with another high-dose multivitamin.

Does AG1 actually do anything?

Evidence for “greens powders” per se is sparse, but AG1 has sponsored human trials on its formula. A 2024 randomised, double-blind, placebo-controlled trial in healthy adults reported that four weeks of AG1 increased certain beneficial gut bacteria and modestly improved digestive symptom quality-of-life scores versus placebo; safety markers remained normal. Effects were small and short-term. (source)

In 2025, the company publicised four placebo-controlled trials (including one triple-blind RCT) suggesting AG1 Next Gen improves nutrient biomarkers (e.g., folate and vitamin C) over ~12 weeks and shows rapid absorption in an acute cross-over bioavailability study. Full peer-reviewed reports are still emerging, so interpret with caution pending independent replication. (source)

While these human trials are of course good, we should keep in mind that these are sponsored trials. Third-party trials by unbiased researchers are yet to be conducted.

Big picture: as a multivitamin/mineral greens drink, AG1 should not be expected to reduce mortality or major disease risk in generally healthy adults; large cohort studies show daily multivitamins do not lower all-cause mortality. Think “fills gaps” rather than “prevents disease.” (source)

Support your immune health with one easy scoop.

With kids back in school, large family gatherings and crazy holiday travel, this time of year, it's more important than ever to be proactive about supporting your immune health.

That’s where AG1 comes in.

AG1 is the Daily Health Drink that contains your daily dose of essential nutrients to support your body’s immune defense and keep you resilient throughout the year.”

Just one scoop every day and you’ll get over 75 ingredients including Vitamin C, Zinc, Antioxidants, and pre/probiotics.

Click HERE to get a FREE AG1 Welcome Kit including an AG1 flavor sample pack, canister and shaker bottle with your first subscription.

Get a FREE AG1 Welcome Kit!

_{*These statements have not been evaluated by the Food and Drug Administration.}

How to take AG1

• Effective dose range: 1 scoop (≈13 g) once daily mixed with 250–300 ml cold water.

• Absorption / timing: Brand suggests first thing on an empty stomach; consistency matters more than timing. If you prefer with food, that’s acceptable.

• Testing / monitoring: If you routinely take high-dose biotin (AG1 contains a lot), schedule susceptible lab tests (e.g., some thyroid markers) at least 8 hours after last dose and flag supplement use to your clinician.

Stack sensibly (optional)

• Vitamin D3 + K2: AG1 omits vitamin D by design; use a separate D3 + K2 if you’re low/indoors (ask for a ‘25-OH D’ blood test with your doctor). Avoid if on vitamin K antagonists.

• Omega-3 (EPA+DHA): complements a multi for cardiometabolic support if dietary oily fish is low (general guidance; not AG1-specific).

Mechanism minute (for the curious)

AG1 mixes essential vitamins, minerals, and plant compounds with fibre and probiotics. The nutrients support normal metabolism and energy production, while the fibre and probiotic strains can encourage a healthier gut environment. Together, they aim to fill small nutrient gaps and support digestion rather than treat any condition.

Safety & cautions

• Pregnancy/trying to conceive: Avoid excess vitamin A; do not combine with other vitamin-A sources like liver/cod liver oil.

• Lab tests: High biotin can interfere with certain immunoassays (e.g., thyroid). Leave an 8-hour gap and inform your clinician.

• GI effects: Fibre/probiotics may cause transient bloating or stool changes; start with half-scoop if sensitive. (General probiotic tolerance; AG1 RCTs reported good safety.)

• Drug interactions: Exercise caution with anticoagulants (vitamin K interplay), thyroid meds (timing vs. minerals), and antibiotics (separate from probiotics).

• Do not megadose: Keep total intake within EFSA ULs (see 1-minute verdict) and avoid stacking with another high-dose multivitamin/mineral.

Our honest thoughts

AG1, like any greens powder, should not be used as an alternative to a healthy diet.

All greens powders are still supplements, and so should be supplemented on the side of an already-healthy diet - we don’t advise a diet of pizza and chips with AG1 on the side.

For many of us it is difficult to find the time to consume a perfect diet, so this is where greens drinks like AG1 can come in. Once you already consume a good variety of fruits, vegetables, nuts, seeds, legumes, grains, and so on, then AG1 is a good option to fill any gaps you might have, if you’re unable to consume enough of each of these plant foods.

We do have a supply of AG1 and other greens drinks that are there for those times when life makes eating well a little more difficult - meeting-heavy days, international travel, long commutes - but a well-balanced diet is key.

Next week: Vitamin D3 — how to dose year-round, what benefits you might experience from trying it, and what blood levels to aim for.

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🛍️ Things You Might Like

Discover the products, services, and retailers we’ve mentioned in past Weekly Health issues, all in one place so you can explore at your own pace.

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🙏 Thanks for Reading!

That’s the end of this issue of Weekly.health.

This newsletter is written by a small, independent team, led by James — who’s been following nutrition science for nearly 20 years and is now working towards a formal, industry-recognised qualification.

We’re based in England, so if you’re over the pond, you might notice a few strange spellings.

Our goal is to make cutting-edge, evidence-based nutrition advice simple, useful, and genuinely applicable to everyday life.

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See you next week!

📖 Glossary of Terms in This Issue (Alphabetical Order)

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