Guide

Does Bio-X4 work? What is in the capsule and what the trials say

Bio-X4 is a capsule taken three times a day that combines four things: five probiotic species, digestive enzymes, green tea extract and Caralluma fimbriata extract. The brand sells it as a four-in-one for weight management and smoother digestion. What separates it from a plain probiotic is that three of the four parts are aimed at appetite, metabolism and meals rather than gut bacteria.

What Bio-X4 is, and what it is not

Each capsule lists a probiotic blend of 4 billion CFU (“at time of manufacture”) naming Lactobacillus acidophilus, L. rhamnosus, L. plantarum, Bifidobacterium lactis and B. animalis; a 43 mg digestive enzyme blend of amylase, bromelain and lipase; 100 mg of green tea extract at 50% EGCG, so about 50 mg of EGCG; and 166 mg of Slimaluma, a branded Caralluma fimbriata extract. At the standard three capsules that is 12 billion CFU, 129 mg of enzymes, about 150 mg of EGCG and 498 mg of Caralluma extract a day. The other ingredients are the vegetable cellulose capsule, microcrystalline cellulose, stearic acid and silica.

The label leaves several things out. There are no strain designations, no per-species counts and no count at expiry. B. lactis is a subspecies of B. animalis, so the five printed names may be four species. The enzyme blend has no activity units, and no caffeine figure is printed for the green tea extract. The brand says every formula is tested at an independent third-party facility but names no laboratory.

The trial of the product itself

There is none. We found no result for Nucific or Bio-X4 in PubMed or ClinicalTrials.gov. The one paper the brand’s page cites is about the Caralluma ingredient, not the capsule.

The evidence for the ingredients

Caralluma (Slimaluma) has three branded-extract trials, all at 1 g a day (500 mg twice daily). In the paper the brand cites, 33 overweight adults finished 12 weeks and waist circumference fell 6.5 cm on the extract against 2.6 cm on placebo (a difference of 3.85 cm, 95% CI 0.23 to 7.47), while weight and BMI fell in both groups (Astell et al., Complementary Therapies in Medicine, 2013). In 83 overweight adults over 16 weeks, the placebo group gained 1.33 kg and the extract group lost 0.37 kg (p = 0.03), waist changed by -2.7 cm against +0.3 cm, and energy intake fell 245 kcal against 15.8; the maker of Slimaluma funded it and supplied the products (Rao et al., Scientific Reports, 2021). Pooling seven trials, the extract lowered waist circumference by 1.59 cm (95% CI 0.10 to 3.07) and waist-to-hip ratio by 0.06, with no significant effect on weight, BMI, hip circumference or appetite measures; a few studies reported constipation, diarrhea, nausea and rashes, and the authors concluded it is unlikely to be recommended as a weight loss or appetite supplement (Jayawardena et al., BMC Complementary Medicine and Therapies, 2021). The dose gap: this label supplies about half the trial dose at three capsules, and about the trial dose only at the six-capsule maximum.

Green tea extract has a Cochrane review for weight loss. In six studies outside Japan (532 participants) the mean weight difference was -0.04 kg (95% CI -0.5 to 0.4); Japanese studies (1,030 participants) ranged from -0.2 to -3.5 kg. The authors called it a small, non-significant weight loss unlikely to be clinically important (Jurgens et al., Cochrane Database of Systematic Reviews, 2012). On safety, a European Food Safety Authority opinion found that 800 mg or more of EGCG a day as a supplement raised liver enzymes in trials; this label gives about 150 mg a day, or 300 mg at six capsules (EFSA Panel, EFSA Journal, 2018).

Probiotics are strain-specific, and this label names none. For body weight, a meta-analysis of 15 trials in 957 people with overweight or obesity found a loss of 0.60 kg (95% CI 0.01 to 1.19) and described the effect sizes as small (Borgeraas et al., Obesity Reviews, 2018). For IBS, a meta-analysis of 82 trials in 10,332 patients rated certainty low to very low for almost every comparison, including combination products (Goodoory et al., Gastroenterology, 2023).

Digestive enzymes have one relevant trial: 120 adults with functional dyspepsia took two capsules a day of a 200 mg fungal enzyme blend for two months and improved quality-of-life and pain scores against placebo (Ullah et al., Biomedicine & Pharmacotherapy, 2023). That blend was 400 mg a day; this label is 129 mg a day with no activity units, and includes bromelain.

How to take Bio-X4

The label says one capsule with each meal, three times a day. It allows up to two capsules per meal and not more than six a day. An older label entry said to take one capsule before eating; the current page says with each meal. A 90-capsule bottle is 30 days at the standard dose. The Caralluma trials ran 12 and 16 weeks, so those are the nearest benchmarks for a fair test.

Side effects and who should not take it

The panel prints no warnings. The brand says to consult your own doctor before starting any supplement, and its materials say to consult a pediatrician before giving it to anyone under 18; Amazon notes that some states prohibit selling weight-loss products to under-18s. We found no pregnancy, nursing or medication statement. Reviewers report stomach pain, bloating, constipation and an unquenchable thirst, and 123 Amazon reviews mention side effects. Caralluma trials reported constipation, diarrhea and nausea in a few participants. Several Amazon reviewers say bottles arrived expired or near their printed dates.

What the reviews say

They split. On Amazon the 90-capsule listing shows 3.8 from 7,236 ratings (51% five-star, 13% four, 15% three, 7% two and 14% one-star); by topic, Amazon counts 297 mentions of effectiveness, 123 of side effects, 121 of appetite control and 110 of value. The brand’s own page shows 4.6 from 4,207 reviews, self-hosted, with a footnote that some reviewers received free products or discounts. Trustpilot gives the whole brand 4.0 from 1,355, with no reviews in the last 12 months. The Better Business Bureau rates Nucific A+ and accredited, with 4.49 from 111 customer reviews and 11 complaints in three years.

The recurring praise is fewer food cravings and less snacking, more regular digestion and less bloating, and more energy. The recurring complaints are no change in weight, stomach problems, and expired or short-dated bottles on Amazon.

The subscription and refund terms

The brand’s 90-day money-back guarantee says to send back the bottle or jars, even empty, for a full refund of the purchase price minus shipping, and to keep the bottles because they must be returned. The clock starts when the order ships. Subscriptions are $44 a month for one bottle, $114 every three months for three or $216 every six months for six. Amazon sells single bottles at $57.95 and marks them non-returnable.

Reviewers on independent platforms describe a recurring pattern, with brand replies. A BBB complaint from January 2025 says a one-bottle order became four through checkout upsell screens and was refunded in full the next day; another says four cancellation requests did not stop payments, and the brand replied that its records show two orders, a return authorization and a cancelled membership. A Trustpilot reviewer wrote that the small print for the 90-day option meant ordering every month, and the brand replied that recurring orders default to monthly and can be changed without changing the price. Others report orders paid but not shipped, refunded after the brand replied, and refunds that required paying to ship back the bottles.

Who Bio-X4 is for

• Someone who wants probiotics, enzymes and an appetite-focused extract in one capsule and will take it at three meals a day.
• Someone for whom cravings are the main goal and who accepts that the Caralluma trials used about twice this label’s dose.
• Someone comfortable keeping the bottles for the 90-day return window.

If gut bacteria are the goal, a probiotic with named strains is a different kind of label; see Culturelle Digestive Daily and Align, the Align vs Culturelle comparison, and the probiotic guide. For enzymes, do digestive enzymes work covers the trials.

Cost

On the brand site one bottle is $99 one time, which is $3.30 a day at three capsules; three bottles are $261.36 and six $487.08. On subscription the figures are $1.47 a day for one bottle, $1.27 for the three-bottle plan and $1.20 for the six-bottle plan. Amazon lists $57.95 a bottle, about $1.93 a day. At the six-capsule maximum every figure doubles.

The products in this catalog

Common questions

Sources

• Astell KJ, Mathai ML, McAinch AJ, et al. "A pilot study investigating the effect of Caralluma fimbriata extract on the risk factors of metabolic syndrome in overweight and obese subjects: a randomised controlled clinical trial." Complementary Therapies in Medicine, 2013;21(3):180–189. doi.org/10.1016/j.ctim.2013.01.004
• Rao A, Briskey D, Dos Reis C, et al. "The effect of an orally-dosed Caralluma Fimbriata extract on appetite control and body composition in overweight adults." Scientific Reports, 2021;11(1):6791. doi.org/10.1038/s41598-021-86108-2
• Jayawardena R, Francis TV, Abhayaratna S, et al. "The use of Caralluma fimbriata as an appetite suppressant and weight loss supplement: a systematic review and meta-analysis of clinical trials." BMC Complementary Medicine and Therapies, 2021;21(1):279. doi.org/10.1186/s12906-021-03450-8
• Jurgens TM, Whelan AM, Killian L, et al. "Green tea for weight loss and weight maintenance in overweight or obese adults." Cochrane Database of Systematic Reviews, 2012;12:CD008650. doi.org/10.1002/14651858.CD008650.pub2
• EFSA Panel on Food Additives and Flavourings. "Scientific opinion on the safety of green tea catechins." EFSA Journal, 2018;16(4):e05239. doi.org/10.2903/j.efsa.2018.5239
• Borgeraas H, Johnson LK, Skattebu J, et al. "Effects of probiotics on body weight, body mass index, fat mass and fat percentage in subjects with overweight or obesity: a systematic review and meta-analysis of randomized controlled trials." Obesity Reviews, 2018;19(2):219–232. doi.org/10.1111/obr.12626
• Goodoory VC, Khasawneh M, Black CJ, et al. "Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis." Gastroenterology, 2023;165(5):1206–1218. doi.org/10.1053/j.gastro.2023.07.018
• Ullah H, Di Minno A, Piccinocchi R, et al. "Efficacy of digestive enzyme supplementation in functional dyspepsia: A monocentric, randomized, double-blind, placebo-controlled, clinical trial." Biomedicine & Pharmacotherapy, 2023;169:115858. doi.org/10.1016/j.biopha.2023.115858
• Brand page and returns FAQ: label, directions, price, subscription and refund terms. nucific.com/bio-x4; nucific.com/returns-faq
• Amazon listing, Trustpilot profile and Better Business Bureau profile for Nucific: ratings, complaints and brand replies. amazon.com; trustpilot.com; bbb.org