Chromium is one of those minerals that gets thrown around a lot in supplement marketing, often with claims about weight loss and blood sugar that sound too good to be true. So what does the research actually show? I’ve gone through the clinical evidence to separate the genuinely useful findings from the hype.

The mineral works as a cofactor for a protein called chromodulin, which helps insulin do its job. That’s the basic mechanism that makes chromium interesting for metabolic health. But “interesting” and “proven effective” are different things, as we’ll see.

Where does chromium come from naturally?

There are two main forms of chromium in nature. Trivalent chromium (chromium III) is the biologically active form found in food. You’ll find it in eggs, nuts, vegetables, mushrooms, asparagus, cheese, and various meats. The actual chromium content varies quite a bit depending on soil conditions, how the food was grown, and when it was harvested.

Hexavalent chromium (chromium VI) is the other form, and it’s worth mentioning because people sometimes confuse them. This form is toxic and carcinogenic. It’s an industrial chemical used in manufacturing processes. This isn’t what’s in food or supplements, but the confusion occasionally causes unnecessary alarm.

Most people get somewhere between 20-35 micrograms of chromium daily from food. Whether that’s “enough” is actually debated because chromium deficiency is rarely documented in people eating normal diets. The question of whether supplements provide additional benefits beyond adequate dietary intake is where things get complicated.

What does the research say about chromium benefits?

1. Blood lipid regulation: limited evidence

Dyslipidaemia, particularly elevated LDL cholesterol, is a well-established risk factor for cardiovascular disease. Could chromium help?

A 2022 systematic review and meta-analysis looked at eight randomised controlled trials and found that chromium supplementation didn’t significantly affect triglycerides, total cholesterol, LDL cholesterol, or HDL cholesterol levels (Tang et al., 2022). However, subgroup analysis suggested that doses above 500 μg/day might reduce triglycerides specifically.

My take: the evidence here is weak. The studies were small and heterogeneous. If you’re concerned about cholesterol, there are interventions with much stronger evidence behind them, like dietary changes and exercise.

2. Oxidative stress: some positive signals

Oxidative stress occurs when reactive oxygen species overwhelm your body’s antioxidant defences. This is linked to diabetes, cardiovascular disease, cancer, and other conditions. Your body has both enzymatic defences (superoxide dismutase, glutathione peroxidase, catalase) and non-enzymatic ones (vitamins C and E, carotenoids, glutathione).

A 2021 meta-analysis of nine trials with 550 participants found that chromium supplementation increased total antioxidant capacity and decreased malondialdehyde (a marker of oxidative damage) (Taghizadeh et al., 2021). Other markers like catalase and glutathione didn’t change significantly.

This is moderately interesting but not conclusive. The clinical relevance of improved antioxidant markers isn’t always clear, and the included studies had significant heterogeneity.

3. Type 2 diabetes: the strongest case

This is where chromium has the most substantial evidence. Type 2 diabetes involves insulin resistance and declining beta cell function, leading to poor blood sugar control and eventually vascular complications. People with diabetes have significantly higher risks of blindness, kidney failure, amputation, stroke, and heart attack compared to the general population (King et al., 1998).

A comprehensive meta-analysis of 28 studies with 1,295 participants found that chromium supplementation improved several diabetes-related markers: lower fasting blood glucose, reduced HbA1c (glycosylated haemoglobin), decreased triglycerides, and higher HDL cholesterol (Asbaghi et al., 2017).

The proposed mechanism involves chromium enhancing insulin binding to receptors, increasing receptor density, and improving beta cell sensitivity.

This doesn’t mean chromium should replace standard diabetes treatment. But it might be useful as an adjunct therapy for some patients. The NHS notes that dietary modifications and medication remain the primary approaches, though some complementary approaches may help certain individuals.

If you have diabetes or concerns about blood sugar, you might also be interested in gymnema sylvestre or bitter melon, which have overlapping research areas. Diabetic bladder dysfunction is one of the lesser-known complications of poorly controlled diabetes.

4. Weight loss: don’t expect miracles

Chromium supplements are heavily marketed for weight loss, supposedly because the mineral increases insulin sensitivity, reduces food cravings, and boosts metabolic rate.

The reality is less exciting. A meta-analysis of 20 randomised controlled trials with 1,038 participants found that while chromium supplementation produced statistically significant weight loss, it wasn’t clinically significant, meaning less than 5% body weight reduction (Onakpoya et al., 2013).

A Cochrane systematic review of nine studies with 622 participants reached a similar conclusion: there’s no reliable evidence supporting chromium picolinate for weight loss in overweight or obese people (Tian et al., 2013).

I’d say skip chromium if weight loss is your primary goal. The effect sizes are tiny, and there are no shortcuts here.

5. Polycystic ovary syndrome: genuinely promising

Polycystic ovary syndrome (PCOS) affects many women during their reproductive years, causing hormonal imbalances, irregular periods, fertility problems, and metabolic issues. The exact causes aren’t fully understood, but insulin resistance and elevated androgens play central roles.

A meta-analysis of seven studies with 351 participants found that chromium supplementation reduced body mass index, fasting insulin levels, and free testosterone in women with PCOS (Fazelian et al., 2016).

This is one area where chromium might genuinely help. The improvements in insulin sensitivity could address one of the underlying drivers of PCOS symptoms. However, it’s still a relatively small evidence base, and chromium should complement rather than replace standard treatments.

6. Binge eating disorder: intriguing but preliminary

Binge eating disorder involves consuming large amounts of food without actual hunger driving it. Around 4% of the population may be affected. Beyond the metabolic consequences of overeating, patients often experience depression and anxiety.

A small double-blind study over six weeks with 24 people found that chromium picolinate reduced fasting blood sugar, binge eating frequency, weight, and depression scores compared to placebo (Brownley et al., 2015).

This is intriguing, but 24 participants is a tiny sample. The study design was solid, but we’d need much larger trials to draw firm conclusions. Consider this early-stage evidence at best.

Side effects and safety concerns

Chromium from food is quite safe. The concerns arise with supplements, where you’re taking concentrated doses.

Recommended supplement doses typically range from 100 to 500 micrograms daily. Going beyond this isn’t advisable since long-term safety data at higher doses is limited.

Potential side effects include:

Skin irritation
Headaches
Stomach pain and nausea
Mood changes
Low blood sugar (hypoglycaemia)

There have been rare case reports, mostly with chromium picolinate, of more serious issues: blood disorders, liver damage, kidney damage, and irregular heart rhythms. Whether these were actually caused by chromium or just coincidental isn’t always clear, but they warrant caution.

The Mayo Clinic notes that while chromium deficiency is rare, supplementation beyond dietary needs isn’t well-supported for most people.

Contraindications: who should avoid chromium supplements

1. Pregnancy, breastfeeding, children, and people with liver or kidney problems The safety data in these populations is insufficient. Don’t experiment.

2. Anyone with chromate allergies If you’ve had reactions to leather jewellery or other chromate-containing products, chromium supplements could trigger allergic responses.

3. People on diabetes medications Chromium can lower blood sugar. Combining it with insulin or oral hypoglycaemic drugs could cause dangerous hypoglycaemia. If you’re managing diabetes, discuss with your doctor before adding chromium.

4. Those with psychiatric conditions There’s some concern that chromium might affect brain chemistry and potentially worsen depression, anxiety, or schizophrenia. The evidence here is limited, but caution seems reasonable.

5. People taking NSAIDs, antacids, or corticosteroids These medications may interact with chromium absorption and could increase the risk of adverse effects.

6. Those on levothyroxine (Synthroid) Chromium may reduce absorption of thyroid medication. If you take levothyroxine, separate the doses by several hours or avoid chromium supplements altogether.

The bottom line

Chromium has some genuine science behind it for type 2 diabetes management and possibly PCOS. For most other promoted uses, including weight loss and cholesterol reduction, the evidence is weak or absent.

If you’re considering chromium supplementation, the diabetes and PCOS research is the most compelling reason. For general health or weight management, your money is probably better spent elsewhere.

As with any supplement, talk to a healthcare provider before starting, especially if you have existing conditions or take medications. The interactions with diabetes drugs and thyroid medication are real concerns, not theoretical ones.

References

Tang H, et al. (2022). Effect of chromium supplementation on lipid profile. Biol Trace Elem Res. PubMed
Taghizadeh M, et al. (2021). Effect of chromium on oxidative stress markers. Biol Trace Elem Res. PubMed
King H, et al. (1998). Global burden of diabetes. Diabetes Care. PubMed
Asbaghi O, et al. (2017). Effect of chromium on glycemic control. J Trace Elem Med Biol. PubMed
Onakpoya I, et al. (2013). Chromium supplementation in overweight and obesity. Obes Rev. PubMed
Tian H, et al. (2013). Chromium picolinate for overweight or obesity. Cochrane Database Syst Rev. PubMed
Fazelian S, et al. (2016). Chromium supplementation in PCOS. Ann Nutr Metab. PubMed
Brownley KA, et al. (2015). Chromium in binge eating disorder. Psychosom Med. PMC