Fulfil Vitamin Protein Bar Review (2026): 20g Protein and 9 Vitamins Per Bar — Nutrition Facts and Honest Comparison

Fulfil Vitamin Protein Bar is the only widely-stocked protein bar at mainstream retail that adds nine vitamins to a 20g protein, 40g format bar. Unlike Quest, ONE Bar, Barebells, or RXBAR, every Fulfil bar fortifies with a meaningful dose of B1, B2, B3, B6, B12, C, D, folate, and biotin — each at approximately 25–33% of the Daily Value. The bar is sweetened with maltitol and sucralose, putting it in the same sweetener category as ONE Bar and Barebells, and the compact 40g size delivers all 20g of protein at roughly 190–200 calories — a higher protein-per-calorie ratio than most bars in this format. Fulfil originated in Ireland and expanded to the US market, where it is now stocked at Target and Walmart. All figures in this guide are from Fulfil’s published 2026 nutrition labels; any value we could not confirm is shown as “—”.

Affiliate links — if you buy through them we earn a small commission at no extra cost to you. Nutrition figures from Fulfil’s 2026 published labels.

Fulfil Vitamin Protein Bar Nutrition Facts: Full Label

One bar is one 40g serving. Per-bar figures below are read directly from Fulfil’s published 2026 label; values are consistent across flavors with minor variation in fat from the chocolate coating.

Values are approximate and drawn from Fulfil’s published label data; individual flavor batches vary by 5–10%. The sugar alcohol count reflects maltitol, which has a moderate glycemic index (~35) and is partially absorbed — see the maltitol section below.

The 9 Vitamins: What You Actually Get Per Bar

Fulfil’s vitamin fortification is the feature that no other major protein bar brand has matched. Each 40g bar delivers approximately 25–33% of the Daily Value for all nine of the following vitamins:

From a practical standpoint, one Fulfil bar covers roughly a quarter of your daily vitamin needs across nine separate micronutrients. That matters most for people with limited dietary variety, anyone eating a restricted-calorie diet where hitting micronutrient targets is harder, or athletes whose B-vitamin requirements are elevated by high training volume. The vitamins are all at food-safe doses — there is no risk of toxicity from eating one or even two bars per day. The vitamin D dose is particularly relevant for populations in lower-sunlight climates, where deficiency is common and protein bars are rarely a source.

Fulfil vs Quest vs ONE Bar vs Barebells vs RXBAR

The comparison below uses each bar’s published label at its standard single-bar serving. Fulfil’s 40g bar is notably smaller than the 55–60g format used by most US competitors, which is why its raw protein count matches them at a lower calorie cost.

The main trade-offs become clear in this table. Fulfil’s protein-per-calorie ratio of 10.3g per 100 cal sits just below Quest (11.1g) but above ONE Bar (9.1g), which is notable given Fulfil’s 40g bar is 20g lighter than Quest and ONE. Fulfil’s calorie efficiency comes from the smaller format, not exceptional macros. The unique selling point is the vitamin stack: no other bar in this comparison fortifies. For people already taking a daily multivitamin the vitamin content is additive but redundant; for people who are not, Fulfil reduces the need. For more on the sweetener comparison, see the maltitol section below. For the full bar landscape, see our best protein bars of 2026 guide.

Maltitol in Fulfil: What to Know Before You Eat Several

Each Fulfil bar contains approximately 15g of maltitol, the same sugar alcohol used in ONE Bar and Barebells. Maltitol differs from erythritol (used by Quest) in three important ways:

• Glycemic index: Maltitol has a glycemic index of approximately 35 — lower than table sugar (65) but meaningfully higher than erythritol (1) or allulose (1). For people managing blood sugar carefully, 15g of maltitol per bar is worth tracking.
• Caloric contribution: Maltitol provides approximately 2.1 kcal per gram (versus 4 kcal for sugar and 0.2 kcal for erythritol), so sugar-alcohol calories are partially counted in the Fulfil label total.
• GI tolerance: Like most sugar alcohols, maltitol can cause gas, bloating, or loose stools when consumed in large amounts. At 15g per bar, most adults tolerate one bar without issue; eating three bars in a sitting (45g maltitol) commonly causes GI distress. This is the same threshold that applies to ONE Bar and Barebells.

If you have found that ONE Bar or Barebells causes digestive issues, Fulfil is likely to produce the same effect at similar quantities. If you are sensitive to erythritol specifically (Quest bars), Fulfil’s maltitol-based formulation is a different compound and may be better tolerated, or may cause the same issues via a different mechanism. The only way to know is to test with a single bar.

Is Fulfil Protein Bar Healthy? Who It’s For

Buy Fulfil Protein Bars if: you want a high-protein snack that also covers roughly a quarter of your daily micronutrient needs across nine vitamins in one bar; you prefer a smaller-format 40g bar over the 55–60g bars most competitors sell (useful for calorie-controlled diets or mid-workout fueling); you find the erythritol in Quest bars causes GI distress (Fulfil uses maltitol, a different compound); or you want a protein bar available at Target or Walmart without ordering online. The vitamin fortification is genuinely unique in the category and adds real value for anyone relying on protein bars as a substantial portion of their daily nutrition.

Consider an alternative if: you are managing blood sugar tightly (15g of maltitol per bar has a moderate glycemic index of ~35 and is partially metabolized, unlike erythritol); you are vegan (Fulfil contains milk protein isolate); you have experienced GI issues from maltitol in ONE Bar or Barebells (Fulfil uses the same compound at similar amounts); or your primary goal is the highest protein per calorie possible (Quest at 11.1g per 100 cal beats Fulfil at 10.3g). See our best high-protein snacks for weight loss guide for a full calorie-efficiency comparison.

Fulfil Protein Bar Flavors (2026)

Five flavors are available in the 2026 US lineup. Macros are consistent across all five, with minor fat variation from the different coatings and fillings:

• Chocolate Peanut Butter: The best-selling flavor; milk chocolate coating over a peanut butter protein filling. Pronounced peanut flavor with a dense, slightly chewy texture.
• Chocolate Fudge Brownie: Dark chocolate coating with a chocolate fudge interior. The richest and most chocolate-forward of the five; recommended if you prefer deep cocoa notes over sweetness.
• Vanilla Caramel: White chocolate or light coating with a caramel-vanilla filling. Sweeter than the chocolate flavors; the maltitol is more perceptible in lighter coatings.
• White Chocolate Cookie Dough: White chocolate coating with a cookie-dough-style filling. The softest texture in the lineup; cookie dough pieces are embedded in the protein layer.
• Chocolate Hazelnut: Milk chocolate exterior with a hazelnut-cream filling inspired by the Nutella profile. Contains hazelnut paste; check ingredients if you have a tree nut allergy.

Where to Buy Fulfil Protein Bars and What to Pay

• Target: The widest US brick-and-mortar availability. Single bars typically $3.00–$3.99 each in the nutrition bar aisle. Stock varies by location; Chocolate Peanut Butter and Chocolate Fudge Brownie are the most consistently stocked flavors.
• Walmart: Single bars available in most stores at $2.98–$3.48. Multi-packs available for order on Walmart.com.
• Amazon: 15-bar boxes typically $30–$42 depending on flavor and whether Subscribe & Save is active — approximately $2.00–$2.80 per bar in bulk. Easiest way to try multiple flavors in one order.

At the single-bar price of $3.00–$4.00, Fulfil is priced comparably to Barebells ($2.50–$3.50 per bar) and slightly above ONE Bar ($2.00–$3.00 per bar). No other bar in this price range includes 9 vitamins. For price-per-gram-of-protein comparisons across the full category, see our cheapest high-protein snacks by price per gram guide.

Frequently Asked Questions

How much protein is in a Fulfil bar?

Each Fulfil Vitamin Protein Bar contains 20g of protein in a 40g bar at approximately 190–200 calories. The protein comes from soy protein isolate and milk protein isolate. At 10.3g of protein per 100 calories, the protein efficiency is slightly below Quest (11.1g) but above ONE Bar (9.1g) at their respective serving sizes.

Does Fulfil protein bar cause digestive issues?

Possibly, at higher quantities. Each bar contains approximately 15g of maltitol, a sugar alcohol that can cause gas, bloating, or loose stools when consumed in large amounts. One bar per day is well-tolerated by most adults; eating several bars in a day increases the risk of GI distress. If you have experienced digestive problems from ONE Bar or Barebells (both of which also use maltitol), Fulfil carries the same risk. If erythritol (found in Quest bars) is specifically what bothers you, Fulfil’s maltitol is a chemically different compound and may or may not have the same effect for you.

What vitamins are in Fulfil protein bars?

Fulfil bars contain 9 vitamins per bar: vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B6 (pyridoxine), vitamin B12, vitamin C, vitamin D, folate (B9), and biotin (B7). Each vitamin is present at approximately 25–33% of the Daily Value per bar. No other mainstream protein bar brand at US retail currently fortifies with all nine of these vitamins at meaningful doses.

Is Fulfil protein bar vegan?

No. Fulfil bars contain milk protein isolate, which is derived from cow’s milk, so they are not suitable for vegans. They may also contain other dairy-derived ingredients depending on the flavor and production line. For vegan-friendly protein bar options, see our best protein bars of 2026 guide, which lists bars by dietary compatibility.

How does Fulfil compare to Quest bars?

Quest bars are slightly more protein-efficient (21g protein for 190 calories, or 11.1g per 100 cal) versus Fulfil (20g for ~195 calories, or 10.3g per 100 cal), and Quest uses erythritol + sucralose instead of maltitol + sucralose, which some people tolerate better. Fulfil’s differentiator is its 9-vitamin fortification, which Quest does not include. Choose Quest if protein per calorie is the primary criterion; choose Fulfil if the vitamin stack adds genuine value for your diet.

Bottom line: Fulfil Vitamin Protein Bar occupies a specific niche: the only widely-stocked protein bar at mainstream retail that adds nine vitamins at meaningful doses to a 20g protein, 40g format bar. At approximately 10.3g of protein per 100 calories it is competitive with ONE Bar and Barebells, and its compact 40g size delivers 20g of protein without the extra 100–130 calories that come with the 55–60g bars. The vitamin fortification is the real differentiator — not a token amount, but roughly a quarter of daily B-vitamin and vitamin D needs in one bar. The maltitol sweetener system is the honest trade-off: the same moderate GI impact and potential GI distress that applies to ONE Bar and Barebells applies here. If you want the cleanest sweetener profile in the category, look at Quest (erythritol) or Ghost (allulose). But if the combination of 20g protein, 9 vitamins, a compact format, and availability at Target or Walmart describes what you are looking for, Fulfil is the clearest current answer. For the full protein bar landscape, see our best protein bars of 2026 guide. Browse the complete protein snacks directory for every option.