According to research reviewed by Gram, a four-week study of 56 overweight adults found that pig collagen supplements did not significantly lower blood pressure or improve heart health markers compared to placebo, with blood pressure dropping only 1 point in both groups.
Researchers tested whether a popular supplement made from pig collagen could help people with extra weight lower their blood pressure and improve their heart health. Over 56 adults took either collagen powder or a placebo for four weeks. The results showed that the collagen supplement didn’t significantly change blood pressure, cholesterol levels, or markers of inflammation in the body. While earlier lab studies suggested collagen might help, this real-world test in humans didn’t find those benefits. The findings suggest that collagen supplements may not be the solution people are looking for when trying to improve their cardiovascular health.
Key Statistics
A randomized controlled trial of 56 middle-aged and older adults found that collagen supplementation decreased systolic blood pressure by only 1 millimeter of mercury in the office setting compared to placebo, which is not clinically meaningful.
Over a 24-hour continuous monitoring period, the collagen group showed no change in systolic blood pressure and only a 2-point decrease in diastolic pressure compared to placebo, far below clinically significant levels.
The four-week study found no significant improvements in cholesterol levels, inflammation markers, blood vessel function in the eyes, or cognitive performance between the collagen and placebo groups.
The Quick Take
- What they studied: Does a collagen supplement made from pigs help lower blood pressure and reduce heart disease risk in people who are overweight?
- Who participated: 56 middle-aged and older adults who were overweight or obese participated in the study. They were randomly assigned to take either collagen powder or a placebo (fake pill) daily.
- Key finding: After four weeks, the collagen supplement group showed virtually no improvement in blood pressure compared to the placebo group. Blood pressure dropped by only 1 point in both the upper and lower numbers, which is not considered meaningful.
- What it means for you: If you’re considering collagen supplements to help with blood pressure or heart health, this study suggests they may not deliver the results you’re hoping for. However, this is just one study, and more research is needed before drawing final conclusions.
The Research Details
This was a randomized controlled trial, which is considered one of the strongest types of scientific studies. Researchers divided 56 adults into two groups: one group received 10 grams of collagen powder daily, while the other group received a placebo (erythritol, a sugar substitute) that looked and tasted similar. Neither the participants nor the researchers knew who was getting the real supplement, which helps prevent bias. The study lasted six weeks total—two weeks of baseline measurement followed by four weeks of taking the supplement or placebo. Researchers measured blood pressure in two ways: once in the office and continuously over 24 hours using portable monitors. They also tested blood samples for cholesterol and inflammation markers, checked the tiny blood vessels in the eyes using special imaging, and assessed thinking and reaction time.
This study design is important because it moves beyond laboratory experiments with cells or animals to test whether collagen actually works in real people. The 24-hour blood pressure monitoring is particularly valuable because it captures natural daily variations rather than just a single office reading. By using a placebo group, researchers could determine whether any changes were due to the supplement itself or simply from people’s expectations or lifestyle changes during the study.
This study has several strengths: it was randomized (reducing bias), included a placebo control group, measured blood pressure continuously over 24 hours (more accurate than single readings), and tracked multiple health markers. However, the study was relatively short (only four weeks), had a modest sample size of 56 people, and focused only on people who were overweight or obese, so results may not apply to everyone. The study was properly registered before it began, which is a sign of good scientific practice.
What the Results Show
The main finding was that collagen hydrolysate supplementation did not meaningfully affect blood pressure. In the office, systolic blood pressure (the top number) decreased by only 1 millimeter of mercury in the collagen group compared to placebo, and diastolic pressure (the bottom number) also decreased by only 1 point. Over the full 24-hour period, systolic pressure showed no change at all, and diastolic pressure decreased by only 2 points—far too small to be considered clinically meaningful. These tiny differences could easily be due to chance rather than the supplement itself. The study also found no significant improvements in other important heart health markers like cholesterol levels, markers of blood vessel dysfunction, or signs of inflammation in the blood.
Researchers also examined the tiny blood vessels in participants’ eyes using special imaging technology, reasoning that if collagen helped blood vessels throughout the body, it should show up there too. No meaningful changes were observed. Cognitive performance and thinking speed remained unchanged, though there was an unexpected small increase in reaction time (people were slightly slower to respond), which the researchers noted was surprising and may have been a chance finding. None of these secondary outcomes showed improvements that would suggest the supplement was working.
Earlier studies in laboratories and with animals had suggested that collagen might help reduce blood pressure and improve markers of blood vessel health. This human study suggests those promising lab results don’t translate into real-world benefits. This is a common pattern in nutrition research—what works in a test tube or in mice doesn’t always work in people. The findings align with other recent research questioning the effectiveness of various supplements for cardiovascular health.
Several limitations should be considered when interpreting these results. The study lasted only four weeks, which may not be long enough to see changes in blood pressure and inflammation markers. The sample size of 56 people is relatively small, which means the study had limited statistical power to detect small effects. The study only included people who were overweight or obese, so results may not apply to people of normal weight. Additionally, the study didn’t track whether participants made other lifestyle changes (diet, exercise, stress) that could affect blood pressure. Finally, we don’t know if longer supplementation periods might eventually show benefits.
The Bottom Line
Based on this study, collagen hydrolysate supplements cannot be recommended as an effective treatment for lowering blood pressure or improving cardiovascular health markers in people who are overweight or obese. If you have high blood pressure, proven approaches like reducing salt intake, exercising regularly, managing stress, and maintaining a healthy weight remain the most evidence-based strategies. Always consult with your doctor before starting any supplement, especially if you take blood pressure medications. (Confidence level: Moderate—this is one well-designed study, but more research is needed.)
This finding is most relevant to people who are overweight or obese and considering collagen supplements specifically for blood pressure or heart health benefits. It’s also important for healthcare providers advising patients about supplement use. People who take collagen for other reasons (like joint or skin health) should note that this study doesn’t address those potential benefits. If you have high blood pressure or heart disease, discuss supplement use with your doctor rather than self-treating.
If you were already taking collagen supplements, you wouldn’t expect to see changes in blood pressure within four weeks based on this study. However, this doesn’t mean you should expect benefits at any timeframe—the study found no meaningful effects even after four weeks of consistent use.
Frequently Asked Questions
Does collagen supplement help lower blood pressure?
A 56-person study found collagen supplements reduced blood pressure by only 1 point compared to placebo over four weeks—too small to be meaningful. Lab studies suggested benefits, but real-world testing in humans didn’t confirm those results.
Can collagen improve heart health and cholesterol?
Research on 56 overweight adults showed collagen supplementation produced no significant improvements in cholesterol levels, inflammation markers, or other cardiovascular health indicators compared to placebo after four weeks.
Why don’t collagen supplements work if lab studies showed promise?
This is common in nutrition research—findings in test tubes and animals often don’t translate to real people. The four-week study duration may have been too short, and individual factors like diet and exercise weren’t controlled.
Who should avoid collagen supplements for blood pressure?
Based on this study of overweight and obese adults, those seeking cardiovascular benefits from collagen may be disappointed. Results may not apply to people of normal weight, and longer studies are needed before drawing final conclusions.
Want to Apply This Research?
- If users are interested in blood pressure management, suggest tracking daily blood pressure readings (morning and evening) along with lifestyle factors like exercise minutes, salt intake, and stress levels. This helps identify what actually affects their individual blood pressure rather than relying on supplements.
- Instead of focusing on collagen supplements, encourage users to track and improve proven blood pressure-lowering behaviors: daily physical activity (150 minutes per week), reducing sodium intake, increasing potassium-rich foods, managing stress through meditation or yoga, and maintaining a healthy weight. These changes have strong scientific evidence.
- Set up weekly blood pressure tracking with reminders to measure at consistent times. Create a dashboard showing trends over 4-week periods to help users see the real impact of lifestyle changes. Include notes on diet, exercise, and stress to identify personal patterns that affect their blood pressure.
This research summary is for educational purposes only and should not be considered medical advice. The findings suggest collagen supplements did not improve blood pressure in this study, but individual results may vary. If you have high blood pressure, heart disease, or are taking medications, consult with your healthcare provider before starting any supplement regimen. Do not stop or change any prescribed medications based on this information. This single study, while well-designed, represents one piece of evidence and should not be the sole basis for health decisions.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.