Review · Circulation and leg comfort

Flush Factor Plus review: a small capsule with a big hormone claim

Flush Factor Plus is sold as a daily capsule for fluid balance in the legs, ankles and feet. We read the label, followed every reference the seller lists, and searched PubMed for each ingredient. The research we found is real, but it was done at doses this capsule cannot contain.

By Grant Whitaker, Editor · Updated October 23, 2026 · 16 studies checked on PubMed

What Flush Factor Plus is (and what it is not)

Flush Factor Plus is a capsule supplement sold through Digistore24 from the official website. The label lists the distributor as Flush Factor Plus of Tallmadge, Ohio. The serving is one capsule a day with a glass of water, and each bottle holds 30 capsules. It is a one-time purchase with no autoship, according to the seller.

The name suggests a digestive "flush", and some readers find it while looking for a gut product. It is not one. The sales page and label are about leg comfort, mobility and fluid balance, and the formula contains no laxative herbs such as senna, cascara or aloe latex. If you were looking for help with digestion or bowel habits, this is the wrong product, and any lasting change in bowel habits is a reason to talk to your doctor rather than shop for a supplement.

The sales page says the formula "helps your body manage the production of AVP", meaning arginine vasopressin, the hormone that tells the kidneys how much water to keep. We come back to that claim below.

What is on the label

The Supplement Facts panel shows a single 500 mg proprietary blend with six ingredients, in this order: pineapple powder (fruit), Asparagus racemosus (shatavari root) extract, L-citrulline DL-malate, black cumin seed extract (Nigella sativa), beet root extract standardized to 50% betaine nitrate, and Hibiscus sabdariffa flower extract standardized to 3% anthocyanins. Other ingredients are a cellulose capsule, brown rice flour, magnesium stearate and silicon dioxide.

No individual amount is disclosed. We do not guess doses, but simple arithmetic sets a ceiling: six ingredients share 500 mg, so the average is about 83 mg each, and none can exceed 500 mg. The vendor's affiliate rules do not grant permission to reproduce its images, so we describe the label here instead of showing it. You can view it on the official site.

The formula next to the research

For each ingredient we looked for human trials on leg swelling or fluid retention first, then on the closest related outcome, which for most of them turned out to be blood pressure.

Hibiscus: the best-studied ingredient, for blood pressure

Hibiscus has the deepest research of the six. A 2022 meta-analysis of 17 trials found that hibiscus lowered systolic blood pressure by about 7 mmHg more than placebo, with the largest drops in people whose pressure started high ^[4]. A 2025 overview pooling 26 trials and 1,797 people reported a dose-dependent effect, with stronger results in people over 50 and in trials lasting more than four weeks ^[5]. None of these trials measured leg or ankle swelling. Because the effect depends on dose and the label gives none, we cannot say whether a share of a 500 mg capsule is in the studied range.

Black cumin: modest blood pressure effects at gram-level doses

Black cumin (Nigella sativa) was tested in 11 randomized trials with 860 people. Compared with control groups, systolic pressure fell by about 3 mmHg and diastolic by about 3 mmHg over an average of 8 weeks ^[6]. Again, these were blood pressure studies. We found no trial of black cumin on leg swelling.

Beet nitrate and citrulline: blood flow ingredients, much smaller here

Dietary nitrate, mostly from beetroot juice, lowered clinic systolic pressure by about 4 mmHg across 13 short trials, though the effect did not show up with 24-hour or home monitoring ^[7]. In the strongest single trial, 68 adults with high blood pressure drank 250 mL of nitrate-rich beetroot juice daily for four weeks and saw clinic pressure fall by 7.7/2.4 mmHg versus placebo juice ^[8]. The seller cites a beetroot juice trial in 23 people with Raynaud's phenomenon, where both nitrate-rich and nitrate-depleted juice improved thumb blood flow after cooling, but skin temperature did not change ^[9]. That study used juice, measured hands and feet after cold exposure, and did not look at swelling.

L-citrulline is an amino acid the body converts to arginine. A 2025 meta-analysis of 15 trials in middle-aged and older adults found that citrulline or watermelon lowered systolic pressure by about 4 mmHg ^[10]. A typical trial in older adults used 6 grams a day ^[11]. The entire Flush Factor Plus capsule weighs one twelfth of that, and it shares the space with five other ingredients.

The seller also lists a 2012 study on oral citrulline and lower-leg swelling in young women. It is the one reference that sounds closest to the product's purpose. We searched PubMed by title, author and topic and could not find it indexed, so we could not check its design, dose or results.

Pineapple and shatavari: supporting cast

Pineapple is the source of bromelain, a mix of enzymes. A meta-analysis of six trials found that bromelain extract modestly reduced facial swelling after wisdom tooth surgery ^[12]. The seller's own bromelain reference is a narrative review of possible uses rather than a trial ^[13]. Flush Factor Plus contains pineapple powder, which is dried fruit, and the label states no bromelain content. For shatavari, a traditional Ayurvedic root, recent trials we found were in women around menopause; none looked at fluid balance or leg comfort.

About the AVP (vasopressin) claim

The central idea on the sales page is that the formula helps the body manage vasopressin, the water-retaining hormone, and that this supports fluid circulation in the legs. We looked for evidence in two ways.

First, we read the two vasopressin papers on the seller's reference list. One is a review of sodium and water disorders in intensive care patients ^[2]. The other is a short published letter about vasopressin given as a drug in severe shock ^[3]. Both describe hospital medicine. Neither mentions any of the six ingredients or leg swelling.

Second, we searched PubMed for randomized human trials pairing each ingredient with vasopressin. We found none. The claim may come from somewhere we did not see, but as of this review we could not trace it to a publication, so we give it no weight.

Where the sales page and the checkout disagree

We noticed a few small mismatches. The sales page says the three bonus guides come with the 6-bottle order, and its FAQ mentions two guides, yet the Digistore24 checkout lists three free e-books with both the 2 + 1 and the 3 + 3 packages. The label reads "Mobility & Flexibility" and "Movement Strength", which are broader than the fluid message on the page. None of this changes the formula, but it is worth knowing what you are buying.

Price, packages and refund policy

One bottle lasts 30 days. Prices on the official site and the Digistore24 checkout when we checked:

• 6 bottles (sold as 3 + 3): $49 each ($294 total), free US shipping, three digital guides. About $1.63 a day.
• 3 bottles (sold as 2 + 1): $69 each ($207 total), free US shipping.
• 2 bottles: $79 each ($158 total), free US shipping. There is no single-bottle option.

The refund policy runs 60 days from delivery. You email support, then mail back every bottle, opened or not, at your own cost. Note that the same policy suggests using the product for at least three months before judging it, which is longer than the refund window. If you test the 6-bottle package and decide against it, the clock runs out halfway through.

Safety

The individual ingredients are common in foods and teas, and the blood pressure trials above generally reported them as well tolerated. A few points matter more for men over 50:

• Blood pressure medicines. Hibiscus, black cumin, dietary nitrate and citrulline each lowered blood pressure in trials ^{[4] [6] [7] [10]}. Together with prescription blood pressure drugs, the effect could add up. Small doses make a large effect unlikely, but tell your doctor.
• Blood thinners. A 2026 case report described a sharp rise in INR in a woman on warfarin after drinking hibiscus tea ^[14], and another described a large bruise-like bleed in a man taking black seed oil with two antiplatelet drugs during chemotherapy ^[15]. Case reports do not prove cause, but they are a reason to check first.
• Kidneys and diabetes. A case report linked black cumin to acute kidney injury in a patient with diabetes ^[16]. If you have kidney disease or diabetes, ask before starting.
• Erection medicines and nitrates. Nitrate and citrulline both work through nitric oxide. If you take nitrate heart medicine or a drug for erections, ask your doctor or pharmacist before combining them with any blood flow supplement.

Most important, a supplement should never stand in for finding out why your legs swell. Chronic swelling in one or both legs often reflects venous insufficiency, and rapidly developing swelling can signal a clot or a body-wide illness that needs timely diagnosis ^[1]. Talk to your doctor before starting Flush Factor Plus, especially if you take any prescription medication, and seek care for swelling that is new, one-sided, painful or getting worse. Results vary from person to person.

What we liked and what gave us pause

Frequently asked questions

Is Flush Factor Plus a gut cleanse or a laxative?

No. Despite the name, it is marketed for leg and fluid comfort, and its label lists no laxative herbs or digestive ingredients.

Where can I buy Flush Factor Plus?

Through the official website, with checkout handled by Digistore24. The seller does not allow listings on Amazon, eBay or other marketplaces, so third-party listings may not be genuine or covered by the refund policy.

How long before I notice anything?

Results vary. The ingredient trials ran from two weeks to a few months and measured blood pressure, not swelling, so there is no research-based timeline for this product.

Can it replace a water pill or compression stockings?

No. Flush Factor Plus is a dietary supplement. Do not stop or change a prescription or a treatment your doctor recommended without talking to them first.

How we reviewed Flush Factor Plus

We read the official sales page, Supplement Facts label, refund and shipping policies and the seller's reference list, and confirmed prices at the Digistore24 checkout. We then searched PubMed for human trials of each ingredient on leg swelling, fluid balance and blood pressure, and for any link between the ingredients and vasopressin. We did not test the product on people, and nobody at Stark Verve is a medical professional. Read our editorial policy to learn how we choose and update reviews. Stark Verve earns a commission if you buy through our links; that never changes what we write about the evidence.