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Cutting Calories On A GLP-1? Don't Cut Protein Or Fiber.

Smaller meals mean less protein to protect muscle and less fiber to keep you regular. One ready-to-pour packet gives you 15g complete protein, 8g fiber from 5 sources and 9g collagen, including clinically proven VERISOL®. Tear, pour into water and sip. No scoop, no shaker, no thick shake.

Fill My Nutrient Gap
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Smaller meals mean less protein to protect muscle and less fiber to keep you regular. One ready-to-pour packet gives you 15g complete protein, 8g fiber from 5 sources and 9g collagen, including clinically proven VERISOL®. Tear, pour into water and sip. No scoop, no shaker, no thick shake.

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Fill My Nutrient Gap
45 Day Money Back Guarantee**

On A GLP-1, You're Losing More Than Fat

82% of GLP-1 users worry about losing muscle, not just fat.³ A 2025 joint advisory names muscle loss, digestive side effects and nutrient deficiencies as priorities to manage during GLP-1 treatment.¹

On A GLP-1, You're Losing More Than Fat

82% of GLP-1 users worry about losing muscle, not just fat.³ A 2025 joint advisory names muscle loss, digestive side effects and nutrient deficiencies as priorities to manage during GLP-1 treatment.¹

On A GLP-1, Less Food Means Fewer Critical Nutrients

Your body's protein, fiber and nutrient needs don't shrink with your appetite. Half a plate carries half of what it used to, so what you do eat and drink has to work harder.

Up To 40% Of GLP-1 Weight Loss Can Be Muscle

In GLP-1 clinical trials, up to 40% of the weight lost was lean mass, not fat.⁴ And in a 2025 study of adults on GLP-1 medications, protein intake fell short of daily needs.² Each packet adds 15g of complete protein to help protect lean muscle.

Protein-Rich GLP-1 Diets Lack Critical Fiber

On a GLP-1, most meals shift toward protein, and protein-rich meals tend to be low in fiber. In the same 2025 study, participants averaged just 14.5g of fiber a day,² well below what adults are advised to get. Each packet adds 8g from five sources.

Losing Weight On A GLP-1, But Still Bloated?

Without enough fiber, things stop moving: you weigh less but feel bloated and backed up. Digestive changes are common on GLP-1 medications,¹ and single-source fiber can make bloating worse. Ours spreads 8g across five gentle, low-FODMAP sources to support regularity.

Worried About GLP-1 Face? So Are 74% Of Users.

74% of GLP-1 users are concerned about changes to their face, skin or hair.³ Each packet has 2.5g of VERISOL® collagen, clinically proven to improve skin elasticity and hydration, at the exact daily dose from its published research.

No Appetite On A GLP-1? Skip The Thick Shake.

So we made the first protein + fiber + collagen that comes ready to pour. It's already dissolved: tear the packet, pour it into cold water and sip a light, 90-calorie drink. No scoop, no shaker, no clumps.

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First Day Adults Protein + Fiber + Collagen 8-in-1 Complex powder in a resealable stand-up pouch, shown with three single-serve packets, a glass of lemonade with lemon slices, and peach and yellow fruit slices on a white background.
A person pours a light yellow drink from a First Day Verisol pouch into a glass with lemon slices. A large bag of First Day Adults protein, fiber, and collagen is visible on the counter behind it, with a text overlay at the top describing the product.
Promotional graphic for First Day Adults Ready-to-Pour Powder Protein, Fiber & Collagen Complex in Peach Mango and Lemonade flavors. The image features two stand-up pouches of the product, with text detailing nutritional benefits (15g protein, 8g fiber, 2.
A promotional graphic with a large blue panel containing survey text about consumer preferences for liquid packets versus powders, shakers, and tubs, alongside a faded photo of a child pouring liquid from a carton into a glass at a kitchen counter.
An infographic-style product graphic on a light blue background with the headline '90%+ of Adults Don't Get Enough Fiber.' It shows three illustrated callouts: '15g Protein,' '8g Fiber,' and 'Light' with a drink and lemon slice, explaining a fiber-and-protein supplement concept.
An infographic-style product graphic with large blue text reading '3X More Nutrients Than Protein Alone' on a pale blue background, plus three benefit callouts: Build Muscle, Improve Skin, Hair & Nails, and Balance Metabolism.
A comparison chart titled 'Ready-To-Pour vs. Powder' on a light blue background.
An informational graphic for a dental composite material called VERISOL, showing three layers: Fiber, Protein, and Collagen. The graphic features a clean white and light blue design with text descriptions of each layer and their benefits, including 'Gentle, 5-source blend supports digestion' for the fiber, 'Grass-fed whey, cultured protein + collagen provide a complete amino acid profile' for the protein, and '2.
Promotional comparison graphic for a protein powder ready-to-pour packet. Left panel titled 'The Old Way (POWDER)' lists steps like scoop, measure, shake, and wait for dissolution.
A promotional graphic for a clear glass tumbler with lemon slices, shown on a light blue background with text describing drink compatibility and sizes. The glass is filled with a pale golden drink, and the design includes flavor callouts such as lemonade, peach mango, and citrus.
Instructional graphic for a fiber supplement drink mix, showing three steps: tear, pour, and drink. The top right shows lemonade being poured into a glass with lemon slices, alongside a bag of the product.
A product comparison graphic for adult protein and fiber + collagen powder, showing two supplement facts panels: Fresh Lemonade and Peach Mango. The left panel is labeled Fresh Lemonade and the right panel Peach Mango, both with blue headers and white supplement fact sections.

Adult Protein + Fiber + Collagen (15 Ready-to-Pour Packets) 8-In-1 Protein + Fiber + Collagen For GLP-1 Users. Replaces 3 Products In 1 Ready-To-Pour Packet.

Complete protein. Fiber from 5 sources. Clinical-dose collagen. One instantly-dissolving drink mix providing protein, fiber, plus 2.5g of VERISOL® collagen, clinically proven to help reduce fine lines and wrinkles. All in one ready-to-pour liquid packet. Tear, pour into water, done. No scoop, no shaker, no clumps.

Build & Maintain Muscle Build & Maintain Muscle
66%

of adults we surveyed don't get enough protein for energy, muscle and metabolism.†

15g of complete protein per packet: Clear Protein (whey isolate) for a fast leucine trigger, cell-based cultured protein for all 9 essential amino acids, and collagen for structure.*

Reduce fine lines & wrinkles Reduce fine lines & wrinkles
2.5g

of clinically studied VERISOL® for to help support elasticity, hydration and fine lines.

Improve hair thickness & strengthen nails Improve hair thickness & strengthen nails
+65%

procollagen synthesis vs placebo at 8 weeks with VERISOL® (Proksch 2014).

2.5g of VERISOL®, exactly the clinically studied dose, clinically shown to increase skin elasticity, reduce wrinkles, strengthen nails and increase hair thickness.*

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15 Servings Per Pack

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Ingredients

Bio-Protein Matrix: bioactive collagen peptides (incl. VERISOL®), cell-based cultured protein (S. cerevisiae), whey protein isolate.

Bio-Adaptive Fiber Blend: organic Jerusalem artichoke (Helianthus tuberosus) (tuber) extract, digestion-resistant dextrin, tapioca fiber, partially hydrolyzed guar gum, acacia fiber.

Sweetened with: stevia (Reb M). No added sugar.

Contains: milk (whey). Free from the other 8 major allergens. Gluten-free. Non-GMO.

Other Ingredients: Water, Citric Acid, Natural Flavors. Less than 2% of: Reb M, Beta-Carotene (For Color), Rowanberry Fruit Extract, Mushroom Extract.
Supplement Facts
Supplement Facts
Subscription Details

Receive a fresh pouch of 15 ready-to-pour packets every 30 days.

Plus, you'll receive these benefits:

  • Savings every single month.
  • Free shipping on your first order.
  • Easy management: skip or pause whenever you need.
  • VIP access to sales, gifts, early access & more.
  • Cancel anytime.

Muscle Loss. Bloat. GLP-1 Face. One Packet Covers All Three.

How This Helps*

Experts recommend adequate protein alongside strength training to help preserve lean mass during GLP-1 therapy.¹ One protein source can't cover every job, so we use three.

🏋️ 15g complete protein with the full amino acid profile to support lean muscle.

🥛 Whey isolate, cultured protein and collagen peptides in one blend.

🚶 Pair it with strength training, as the advisory recommends.

Already Paying For A GLP-1? Stop Buying 3 Separate Tubs.

A protein powder, a fiber supplement and a collagen tub add up fast. 77% of GLP-1 users wish one product covered all three,³ so we made the first ready-to-pour packet that does, with clinically proven VERISOL® collagen in every pour.

15g
Complete Protein

Protects Lean Muscle

Three protein sources with the full amino acid profile. When you're eating less on a GLP-1, every gram has to count.

8g
Fiber From 5 Sources

Prevents Bloat, Improves Regularity

Five gentle, low-FODMAP sources instead of one big dose, to keep you regular without the bloating single-source fiber is known for.

9g
Collagen Peptides

Helps Fight GLP-1 Face

Includes 2.5g of VERISOL®, clinically proven to improve skin elasticity and hydration and support hair and nails.

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Trusted By Experts and Families Like Yours

Dr. Lei Chen

"These vitamins are exactly what I recommend to parents looking for quality nutrition."

Dr. Lei Chen

MD, MHS at Yale University

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Diana V.

"These are the best tasting vitamins I ever purchased. It feels like I am having a treat. These are the only ones so far that my kids like too."

Diana V.

Verified Purchaser

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"A revolutionary approach to children's health."

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Dr. Ed Giovannucci

"We choose partners carefully, and First Day’s dedication to research, formulation integrity, and transparent quality practices makes them a brand we’re proud to align with."

Dr. Ed Giovannucci

MD, MPH, ScD at Harvard University

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Why Should You Choose First Day?

On a GLP-1, there's no room for a protein shake, a fiber supplement and a collagen powder in one day.

First Day
Adult Protein Powders
Protein, fiber + collagen in 1 packet
8g fiber from 5 sources
Dissolves instantly, no blender
No added sugar
Gluten-free and non-GMO
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Your GLP-1 Is A Step In The Right Direction

You Started A Healthier Path. Make Sure Your Nutrition Keeps Up.

Starting a GLP-1 is a big step for your long-term health. Protect it: one ready-to-pour packet a day covers the protein, fiber and clinically proven VERISOL® collagen a smaller appetite leaves behind, from week one.

Get Started Now

FAQs

Can I take this with my GLP-1 medication?

This is a food-based supplement with protein, fiber and collagen, not a medication. Check with your prescriber before adding any supplement, especially if you're managing digestive side effects.
What makes it first of its kind?

Protein, fiber and collagen have always come as separate tubs and powders. Our 8-in-1 complex brings three protein sources, five fibers and VERISOL® collagen together in one ready-to-pour liquid packet, a combination that hasn't been done in this format before.
Is this a meal replacement?

No. It's designed to fill protein and fiber gaps alongside the meals you are eating, not to replace them.
Will the fiber upset my stomach?

The fiber is spread across five gentle, low-FODMAP sources instead of one large dose, which is designed to avoid the bloating common with single-source fiber supplements.
Do I still need a multivitamin?

Protein + Fiber covers protein, fiber and collagen. It isn't a multivitamin. Experts also recommend paying attention to vitamins and minerals during GLP-1 therapy,¹ so ask your provider whether a multi is right for you. First Day makes a Women's Multi and a Men's Multi.
Should I add a probiotic?

Some people like extra digestive support. Our 3-in-1 Pre+ Post+ Probiotic combines prebiotics, probiotics and postbiotics in one daily gummy. It comes in Women's and Men's versions. Check with your provider first.
How do I take it?

It's ready to pour, so there's nothing to scoop or blend. Tear open one packet, pour it into 15 to 24 fl oz of cold water, shake for 5 seconds and drink. It also works in smoothies and blended drinks.
Does it contain any allergens?

Yes. It contains whey protein, which is milk. It's gluten-free and non-GMO.
Should I subscribe if I've never tried First Day before?

Subscribing gets the lowest price, and you can cancel anytime. Every first order is covered by our 45-day money back guarantee.