Water retention in the body: what helps, and what the research says

For water retention in the body, which most often shows up as swollen legs and ankles by the evening, the measures that help most are movement, light compression socks, raising your legs and eating less salt. Compression at 10 to 20 mmHg is backed by a meta-analysis of 11 randomised trials, and among plants the best recognised one for the feeling of heavy legs is melilot, also known as sweet clover, which has its own monograph from the European Medicines Agency.

The first part explains why fluid collects in the legs in particular and which everyday measures have the best research behind them. The second part answers the question of what to take for heavy, swollen legs: which ingredients have been tested, at what doses and in whom.

What helps with water retention in the body? An overview by strength of evidence

Why does water collect in the legs?

Fluid constantly seeps from the blood through the walls of the smallest vessels into the tissues. Older textbooks taught that most of it is reabsorbed at the far end of those vessels. More recent physiology, summarised by Levick and Michel in Cardiovascular Research in 2010, shows otherwise: in most tissues at rest, a slight outward flow prevails, so the fluid has to be carried away by the lymphatic system. Lymph vessels collect it and return it to the blood, and the lymph nodes along the way are also part of the immune system.

When you stand or sit, gravity adds to this. Blood from the legs returns to the heart mainly with the help of the calf muscles, which squeeze the deep veins with every step. When the muscles are still, so is the pump. Muscle movement, breathing and posture also affect the lymphatic system, which is why some swelling by the evening is normal: in a study published in Dermatologic Surgery, the lower leg of healthy volunteers grew by 62 to 94 ml over seven hours.

The NHS lists common causes of swollen ankles, feet and legs as standing or sitting in the same position for too long, eating too much salty food, being overweight, being pregnant, taking certain medicines such as some blood pressure medicines, varicose veins and thyroid problems.

Movement: the fastest fix for swollen legs

The most direct way to get the calf muscle pump working again is to move. In a study in the European Journal of Applied Physiology, six volunteers sat for eight hours with one leg kept still and the other free to move. The still foot swelled by 5.7%, the moving foot by 2.7%, so by half as much. The study is small, but it measures exactly what happens at a desk.

A study in Ergonomics (2000) pointed the same way: with an office chair's tilt locked, calf volume rose by 1.2% on average in 30 minutes, and with the chair free to move it fell by 0.7%. The author notes that earlier research had already shown that repeated walking breaks reduce swelling of the feet and legs.

In practice: get up and walk whenever you can, and while seated, lift your heels and toes and circle your ankles several times.

Compression socks: what the research shows

Compression socks are the measure with the best evidence in this article. A meta-analysis by Amsler and Blättler, published in 2008 in the European Journal of Vascular and Endovascular Surgery, pooled 11 randomised trials with 1,453 people, including 794 healthy people exposed to various forms of strain. Socks at 10 to 20 mmHg had a clear effect on swelling and symptoms compared with placebo or no socks. No study found a difference between 10 to 20 mmHg and more than 20 mmHg, so the authors conclude that 10 to 15 mmHg is enough.

Two smaller studies show what that looks like in numbers. In 12 volunteers, socks at 11 to 21 mmHg reduced or completely prevented evening swelling. In 108 hairdressers, who spend most of their working day on their feet, socks at 15 to 20 mmHg reduced lower leg volume by 19 ml on average and pain and feelings of swelling by about 12%.

On flights of more than five hours, a Cochrane review of 12 trials with 2,918 passengers found less leg swelling in those who wore compression socks.

One important exception: if only one leg has suddenly swollen, socks are not the first step but a reason to get checked (see the section on when to see a doctor).

Raising your legs and comfortable shoes

Raising your legs works for a simple reason: gravity helps return blood and fluid towards the heart. In a study of 25 healthy people (Journal of Plastic, Reconstructive & Aesthetic Surgery, 2013), raising the leg to 47 cm reduced blood pooling in the surface veins by 28%. The same study found that skin blood flow falls slightly when the leg is raised, so there is no need to lift it high. A chair or a pillow is enough.

The NHS also recommends wide, comfortable shoes with a low heel and soft sole, and advises against clothes, socks or shoes that are too tight and against standing or sitting for long periods without a break.

Salt: what really matters for water retention

The NHS names eating too much salty food as a common cause of swollen legs. The World Health Organization advises adults to eat less than 5 g of salt a day, and the NHS sets the limit at no more than 6 g a day, around one level teaspoon. Most of it does not come from the salt shaker: around three quarters of the salt we eat comes from packaged and everyday foods such as bread, breakfast cereals, meat products and ready meals.

The best randomised data on salt and feeling puffy come from the US DASH-Sodium trial. In 412 adults who each ate low, medium and high sodium diets for a month at a time, the high intake raised the risk of bloating by 27%.

In practice, you save the most by cutting down on bread, breakfast cereals, processed meats, cheese and ready meals, rather than on the salt shaker.

Do herbs that increase urine output work?

Dandelion, field horsetail, nettle and birch leaves are classic ingredients of teas and supplements for fluid balance. For two of them, it is more than folklore.

Dandelion. In 2021 the European Medicines Agency's herbal committee adopted a monograph for dandelion root with the traditional-use indication "to increase the amount of urine to achieve flushing of the urinary tract". In a 2009 pilot study (Journal of Alternative and Complementary Medicine), 17 volunteers took 8 ml of a fresh leaf extract three times over a single day. After the first dose they urinated more often, and after the second they passed more urine relative to what they drank.

Field horsetail. In a randomised double-blind trial in 36 healthy men (2014), a standardised dry extract at 900 mg a day increased water excretion over four days to a similar degree as the diuretic hydrochlorothiazide at 25 mg, without meaningful changes in electrolyte excretion.

What this means in practice: these plants act on urine output, not on the calf muscle pump and not on long hours of sitting, so they complement the measures above rather than replace them. When you compare products, check whether the label states the share of the marker compound, because a milligram figure without it does not tell you how much you are actually getting. Dandelion in standardised form is also in the product covered in the second part of this article. If you take medicines for your heart, kidneys or blood pressure, talk to your doctor before using preparations like these.

In short: six steps against water retention

1. Keep moving when sitting and standing: heel raises, ankle circles, short walks.
2. If you stand or sit a lot, try socks at 10 to 20 mmHg. Higher pressure added no benefit in trials.
3. Raise your legs in the evening, on a chair or a pillow.
4. Cut down on salt, especially from bread, breakfast cereals, processed meats, cheese and ready meals.
5. Wear comfortable shoes and avoid socks and clothes that are too tight.
6. If you are looking for support from a supplement, compare composition and dose as described below.

What to take for heavy, swollen legs?

For heavy, swollen legs, four plant options are the best documented: melilot, horse chestnut seed extract, the diosmin and hesperidin combination known as MPFF, and butcher's broom. Melilot is the only one of them for which the European Medicines Agency's Committee on Herbal Medicinal Products (HMPC) has adopted a monograph with the traditional-use indication to relieve symptoms of discomfort and heaviness of legs related to minor venous circulatory disturbances. It is also the only one of the four you can get in standardised form in a food supplement rather than only in a medicine.

Below, the Golden Tree product comes first, followed by the best-known ingredients worldwide with the doses used in research.

1. Golden Tree Lymph Relief: melilot, dandelion, bromelain, selenium and iodine in two capsules

Golden Tree, a European food supplement brand, built Golden Tree Lymph Relief around the lymphatic system and the everyday movement of fluid through the body. Long hours of sitting, little movement and tight clothing all affect how heavy your legs feel, and the lymphatic system itself is influenced by muscle movement, breathing and posture. The formula combines plant extracts that European tradition associates with the legs and with fluid balance, plus selenium and iodine.

Melilot is the lead ingredient in this formula and the best recognised one. On 21 November 2017 the HMPC adopted a monograph for the aerial parts of melilot with the traditional-use indication of relieving discomfort and heaviness of the legs. The accompanying assessment report describes two clinical studies: in an open study of 20 patients, 200 mg of dry extract a day over 15 days significantly reduced ankle oedema, nocturnal cramps and feelings of heaviness, and in an observational study of 4,536 patients, results after three to eight months were good in 70% of patients. The HMPC writes that these results support the traditional use.

The dose in Lymph Relief sits inside the documented range. A daily dose of two capsules provides 35.3 mg of melilot extract with 17% coumarin, which is 6 mg of coumarin. The German Commission E lists melilot preparations in amounts corresponding to 3 to 30 mg of coumarin a day, and the study in 4,536 patients used 4 to 8 mg of an extract standardised to 20% coumarin. Lymph Relief therefore sits inside the Commission E range and, measured as coumarin, above the dose used in that study.

Dandelion is included at 200 mg of extract with 3% cynarin. For dandelion root, the HMPC adopted a monograph in 2021 with the traditional-use indication of increasing the amount of urine.

Selenium and iodine are the two parts of the formula with authorised EU health claims. The lymph nodes that filter fluid along the way are part of the immune system, and that is exactly where an authorised claim applies: selenium contributes to the normal function of the immune system. In addition, selenium contributes to the protection of cells from oxidative stress, iodine contributes to normal energy-yielding metabolism and iodine contributes to the maintenance of normal skin. With 55 µg of selenium (100% NRV) and 90 µg of iodine (60% NRV), the product meets the conditions for all four claims.

Bromelain from pineapple is included at 140 mg with a stated enzyme activity of 28 GDU. Enzyme activity is a figure most bromelain products leave off the label, and without it the milligram number says little.

Golden Tree Lymph Relief at a glance

Before you compare: how to read the label on leg products

• For melilot, look for the coumarin share. Without it you do not know how much of the marker compound you are getting. The documented range is 3 to 30 mg of coumarin a day.
• For horse chestnut, look for escin. The trials used 50 mg of escin twice a day.
• For diosmin, check the form. The MPFF research used a micronised purified flavonoid fraction of 90% diosmin and 10% hesperidin.
• For bromelain, look for enzyme activity in GDU or FIP units, not just milligrams.
• Check whether you are buying a medicine or a food supplement. Both have their place, but the rules and the instructions for use differ.

2. Horse chestnut seed extract: the most randomised trials

A Cochrane review (Pittler and Ernst, 2012) pooled 17 randomised trials in people with chronic venous insufficiency. In six trials with 502 participants, lower leg volume fell by an average of 32.1 ml more with horse chestnut seed extract than with placebo. Leg pain improved in six of the seven trials that reported it, and side effects were mild and infrequent.

In a trial published in The Lancet in 1996 with 240 patients, leg volume fell by 43.8 ml after 12 weeks with an extract providing 50 mg of escin twice a day and by 46.7 ml with class II compression stockings, while it rose by 9.8 ml on placebo.

In the UK, horse chestnut tablets are sold as registered traditional herbal medicines, with the registered indication "used for relieving the symptoms of varicose veins, based on traditional use only". That is a different legal category from a food supplement, which is worth knowing when you compare products.

• Dose in trials: 100 mg escin a day (50 mg twice a day), 12 weeks
• Who was studied: people with chronic venous insufficiency

3. Diosmin and hesperidin (MPFF): the most trials on vein symptoms

MPFF is a micronised purified flavonoid fraction of 90% diosmin and 10% hesperidin. A meta-analysis of seven double-blind trials with 1,692 patients with chronic venous disease (Kakkos and Nicolaides, 2018) found less heaviness, feeling of swelling, pain and cramps than with placebo, and a smaller ankle circumference. For heaviness, one extra person improved for every two people treated, compared with placebo. The meta-analysis was carried out on one specific licensed medicine, whose brand name appears in the title of the paper.

A broader Cochrane review of all vein medicines (2020, 56 studies with 7,690 participants) was more cautious: moderate-certainty evidence suggests this group of medicines probably reduces leg swelling slightly, ankle circumference by 4.3 mm on average.

In EU countries MPFF is licensed as a medicine, in Slovenia for example at one 500 mg tablet twice a day.

• Dose in trials: 1,000 mg MPFF a day
• Who was studied: people with chronic venous disease

4. Butcher's broom (Ruscus aculeatus): the results apply to the combination

A meta-analysis of ten double-blind trials with 719 patients (Kakkos and Allaert, 2017) assessed products combining butcher's broom extract with hesperidin methyl chalcone and vitamin C. Compared with placebo, they reduced heaviness, pain, tired legs and feelings of swelling, as well as ankle circumference and leg volume. The result applies to that combination, not to butcher's broom on its own, and this meta-analysis too was carried out on one specific licensed preparation.

• Dose in trials: combination products, individual doses are not given in the abstract
• Who was studied: people with chronic venous disease

5. Red vine leaf extract: two trials, different results

The same standardised extract, coded AS 195, was tested in two randomised trials lasting 12 weeks each. In 260 enrolled patients with mild chronic venous insufficiency, lower leg volume fell by 75.9 g at 360 mg a day and by 99.9 g at 720 mg a day more than with placebo (Kiesewetter and colleagues, 2000; volume was measured by water displacement and reported in grams in the original). In 248 patients with swelling and skin changes, 720 mg a day reduced volume by 19.9 ml more than placebo (Rabe and colleagues, 2011, a trial funded by the maker of the extract).

• Dose in trials: 360 to 720 mg of standardised extract a day
• Who was studied: people with chronic venous insufficiency

6. Pine bark extract: popular, but little evidence

A Cochrane review from 2020 covered 27 trials across ten conditions. For chronic venous insufficiency there were only two studies with 60 participants in total, and the certainty of the evidence was very low.

• Who was studied: 60 people in two studies

Comparison: doses and where to get them

When swollen legs need a doctor

Swollen legs are common and usually harmless, but sometimes they are a sign that should be checked. The NHS advises seeing a GP if both legs are swollen and have not improved after treating them at home for a few days, or are getting worse, or if you have been diagnosed with a condition that affects your heart, kidneys or leg veins. Get help from NHS 111 if only one leg is swollen and you do not know why, if the swelling is severe, painful, very sudden, red or hot to the touch, if your temperature is very high, or if you have diabetes and your legs are swollen. Call 999 if you also have shortness of breath, chest pain or are coughing up blood, as these can be signs of a blood clot in the lungs.

Two things are worth adding: most trials of extracts and medicines for heavy legs were done in people with chronic venous insufficiency, and the effects are moderate, a few dozen millilitres of leg volume or a few millimetres of ankle circumference. Food supplements are also not a substitute for a varied and balanced diet and a healthy lifestyle.

Frequently asked questions

What is best studied for heavy, swollen legs? Among plant ingredients, the best documented are melilot, which has a European Medicines Agency monograph for traditional use in heaviness of the legs, and horse chestnut seed extract, with a Cochrane review of 17 trials (leg volume 32.1 ml lower on average than placebo). The most trials on vein symptoms belong to MPFF made of diosmin and hesperidin, which is licensed as a medicine.

Which food supplement contains melilot at a documented dose? Golden Tree Lymph Relief provides 35.3 mg of melilot extract standardised to 17% coumarin in a daily dose of two capsules, which is 6 mg of coumarin. That sits inside the 3 to 30 mg range of coumarin a day that the German Commission E lists for melilot preparations, and above the dose used in the observational study of 4,536 patients. The product also contains 200 mg of dandelion extract, 140 mg of bromelain (28 GDU), 300 mg of purple coneflower extract, 55 µg of selenium and 90 µg of iodine. Selenium contributes to the normal function of the immune system.

What helps water retention in the legs fastest? Movement: in a study of eight hours of sitting, the foot that moved swelled half as much as the still one. Raising your legs and compression socks at 10 to 20 mmHg also help, and compression has the best evidence of all the measures.

Does salt really cause water retention? According to the NHS, eating too much salty food is a common cause of swollen legs. The NHS limit is no more than 6 g of salt a day, and around three quarters of what we eat comes from packaged and everyday foods. In the DASH-Sodium trial, a high sodium intake raised the risk of bloating by 27%.

Does drinking more water help with water retention? Fluid collects in the legs because of gravity and a resting calf muscle pump, not because you drink too little, so drinking more on its own will not take the swelling away. The general NHS advice is 6 to 8 glasses of fluid a day, and lower-fat milk and sugar-free drinks count towards that. You need more in hot weather, during long periods of physical activity, in pregnancy, while breastfeeding and when you are ill.

How long should you take a supplement for your legs? Think in weeks, not days. The melilot studies ran from 15 days to eight months, and trials of other extracts usually 12 weeks. Golden Tree Lymph Relief is suitable for long-term use as part of a balanced diet, and a pack of 60 capsules lasts 30 days.

Where to start

Start with movement, because it works straight away and costs nothing: lift your heels and toes several times while seated, and put your legs up on a pillow in the evening. If you spend most of the day standing or sitting, try socks at 10 to 20 mmHg, and when it comes to food, cut back on bread, processed meats and ready meals first.

If you want to add a supplement to that, Golden Tree Lymph Relief is put together for exactly this. Two capsules with breakfast, with a 60-day money-back guarantee. More on nutrition and everyday habits is on the Golden Tree blog.