Pumpkin seed oil supplementation increased testosterone levels by 5% and decreased estradiol by 14% in men with early-stage gynecomastia, according to a 2026 study in the Journal of the American Nutrition Association. Gram Research analysis shows men’s symptom severity dropped by roughly 50%, with 85% experiencing no side effects, suggesting pumpkin seed oil may be a safe natural option for hormone-related breast tissue growth in men.
A new study from the Journal of the American Nutrition Association examined whether pumpkin seed oil could help men with early-stage gynecomastia—a condition where breast tissue grows due to hormone imbalances. Researchers gave men aged 18-50 with this condition pumpkin seed oil supplements for several weeks and measured their hormone levels before and after. The results showed that pumpkin seed oil increased testosterone levels by about 5% and decreased estradiol (a form of estrogen) by about 14%. Men also reported that their symptoms improved significantly, and most participants experienced no side effects. According to Gram Research analysis, these findings suggest pumpkin seed oil could be a safe, natural option to help manage hormone-related breast tissue growth in men.
Key Statistics
A 2026 study published in the Journal of the American Nutrition Association found that pumpkin seed oil supplementation increased testosterone levels by 5% (from 513 to 539 ng/dL) in men with early-stage gynecomastia.
According to the same 2026 research, pumpkin seed oil decreased estradiol levels by 14% (from 30.8 to 26.4 pg/mL) while reducing symptom severity scores by approximately 50% in men with gynecomastia.
The 2026 study reported that 85% of men taking pumpkin seed oil experienced no adverse effects, indicating the supplement was well-tolerated across the participant group.
Gram Research analysis of the 2026 pumpkin seed oil study shows clinical symptom severity improved from 2.5-3.0 to approximately 1.2 on the severity scale, representing significant symptom relief in men with early-stage gynecomastia.
The Quick Take
- What they studied: Whether pumpkin seed oil supplements could help men with early-stage gynecomastia (enlarged breast tissue) by improving their hormone balance and reducing symptoms.
- Who participated: Men aged 18-50 years with early-stage gynecomastia who had stable eating and exercise habits. The study excluded men with serious health conditions or pumpkin allergies.
- Key finding: Pumpkin seed oil increased testosterone levels by 5% and decreased estradiol levels by 14% over the study period. Men’s symptom severity scores dropped from 2.5-3.0 to about 1.2, showing significant improvement.
- What it means for you: If you’re a man with early-stage gynecomastia, pumpkin seed oil might help balance your hormones naturally with minimal side effects. However, this is one study, so talk to your doctor before starting any supplement to make sure it’s right for your situation.
The Research Details
Researchers recruited men aged 18-50 with early-stage gynecomastia and gave them standardized pumpkin seed oil supplements for several weeks. Before and after the treatment, they measured the men’s testosterone and estradiol levels using blood tests. They also asked men to rate how severe their breast tissue symptoms were using a scoring system. Throughout the study, researchers watched for any side effects by observing participants and asking them about their experiences.
Pumpkin seed oil was chosen because it contains omega-3 fatty acids, phytosterols (plant compounds), and zinc—all nutrients that may influence hormone production. The researchers wanted to see if these natural compounds could help restore hormone balance without the side effects of prescription medications.
The study design allowed researchers to compare each man’s hormone levels and symptoms before and after treatment, making it possible to see whether the pumpkin seed oil actually made a difference.
This research approach is important because it tests a natural, accessible supplement that men might be able to use at home. Rather than jumping straight to prescription treatments or surgery, doctors and patients need to know whether natural options like pumpkin seed oil can actually help. This study provides real-world evidence about whether the nutrients in pumpkin seed oil translate into measurable hormone changes and symptom relief.
This study measured specific, objective outcomes like hormone levels through blood tests, which is more reliable than just asking men how they feel. The fact that 85% of participants reported no side effects suggests the supplement was well-tolerated. However, the study doesn’t specify exactly how many men participated, which makes it harder to judge how reliable the results are. The study also doesn’t mention whether there was a control group (men who took a placebo instead), which would strengthen the findings. Published in the Journal of the American Nutrition Association, this research adds to the scientific literature on natural supplements, though larger, more rigorous studies would help confirm these results.
What the Results Show
Pumpkin seed oil supplementation produced measurable changes in men’s hormone levels. Testosterone increased from an average of 513 ng/dL to 539 ng/dL—a gain of about 5%. At the same time, estradiol (a form of estrogen that can contribute to breast tissue growth) dropped from 30.8 pg/mL to 26.4 pg/mL, a decrease of about 14%. These changes suggest that pumpkin seed oil helped shift the hormone balance in a direction that could reduce gynecomastia.
Beyond hormone levels, men experienced real symptom improvement. The severity of their breast tissue symptoms—measured on a scale—dropped from 2.5-3.0 down to about 1.2. This roughly 50% reduction in symptom severity is significant and suggests that the hormone changes translated into actual relief from the condition.
Safety was excellent: 85% of participants reported no adverse effects at all. The remaining 15% who did experience side effects had only minor issues, and the study notes that supplementation was well-tolerated overall. This is important because it means men could potentially use pumpkin seed oil without worrying about serious health risks.
The study found that pumpkin seed oil’s benefits appeared consistent across the group of men studied, suggesting the supplement works similarly for different individuals with early-stage gynecomastia. The fact that symptom improvement closely followed hormone changes suggests that the hormone-balancing effect is what actually reduces the breast tissue growth. The minimal side effect profile is notable because it contrasts with some prescription hormone treatments, which can cause unwanted effects.
This research builds on earlier studies showing that pumpkin seed oil contains compounds (phytosterols, omega-3 fatty acids, and zinc) that may influence hormone production. Previous research has suggested these nutrients support testosterone production and may help regulate estrogen levels. This study is one of the first to specifically test whether pumpkin seed oil can help men with gynecomastia, filling a gap in the research on natural treatments for this condition. The hormone changes observed here are consistent with what scientists would expect based on the oil’s nutrient composition.
The study doesn’t specify the exact number of participants, making it difficult to assess how reliable the results are. Without a control group (men taking a placebo), we can’t be completely certain the improvements came from the pumpkin seed oil rather than other factors like placebo effect or lifestyle changes. The study only looked at men aged 18-50 with early-stage gynecomastia, so results may not apply to older men or those with more advanced cases. The duration of the study isn’t clearly stated, so we don’t know how long men took the supplement or whether benefits lasted after stopping. Finally, this is a single study, so larger, more rigorous research is needed to confirm these findings before doctors widely recommend pumpkin seed oil for gynecomastia.
The Bottom Line
If you’re a man with early-stage gynecomastia, pumpkin seed oil supplementation appears to be a safe option worth discussing with your doctor. The evidence shows it may help balance hormones and reduce symptoms, with minimal side effects. However, this is one study, so confidence in these recommendations is moderate. Start with a conversation with your healthcare provider to ensure pumpkin seed oil won’t interact with any medications you’re taking and to rule out other causes of gynecomastia that might need different treatment.
Men aged 18-50 with early-stage gynecomastia are the primary group who should consider this research. Men with more advanced gynecomastia, those with serious health conditions, or those with pumpkin allergies should not use this supplement without medical guidance. Women and men without gynecomastia won’t benefit from this treatment. Anyone taking hormone-related medications should consult their doctor before starting pumpkin seed oil.
Based on this study, men took the supplement for several weeks before seeing measurable hormone changes and symptom improvement. You shouldn’t expect overnight results—plan to use pumpkin seed oil consistently for at least several weeks before evaluating whether it’s working for you. Some men may see benefits sooner, while others may need longer. If you don’t notice improvement after 8-12 weeks of consistent use, talk to your doctor about other options.
Frequently Asked Questions
Can pumpkin seed oil actually help reduce man boobs?
A 2026 study found that pumpkin seed oil supplementation reduced symptom severity by about 50% in men with early-stage gynecomastia by increasing testosterone and decreasing estradiol levels. Results were significant, though this is one study and larger research is needed to confirm effectiveness.
How much does testosterone increase from taking pumpkin seed oil?
In the 2026 research, testosterone levels increased by approximately 5% (from 513 to 539 ng/dL) after pumpkin seed oil supplementation. While modest, this increase occurred alongside a 14% decrease in estradiol, suggesting a meaningful hormone shift.
Is pumpkin seed oil safe to take for gynecomastia?
According to the 2026 study, 85% of men experienced no side effects from pumpkin seed oil supplementation, and the remaining 15% reported only minor issues. The supplement appeared well-tolerated, though you should consult your doctor before starting any supplement.
How long does it take for pumpkin seed oil to work for breast tissue?
The 2026 study showed measurable hormone changes and symptom improvement after several weeks of consistent supplementation. Most men should expect to take pumpkin seed oil for at least 8-12 weeks before fully evaluating whether it’s working for their specific situation.
What makes pumpkin seed oil help with hormone balance?
Pumpkin seed oil contains omega-3 fatty acids, phytosterols, and zinc—nutrients that research suggests support testosterone production and may help regulate estrogen levels. These compounds appear to shift hormone balance in a direction that reduces gynecomastia symptoms.
Want to Apply This Research?
- Log your daily pumpkin seed oil supplementation dose and time taken. Rate your gynecomastia symptom severity weekly on a scale of 1-10 (1 = no symptoms, 10 = severe). Track any physical changes you notice in breast tissue appearance or tenderness.
- Set a daily reminder to take your pumpkin seed oil supplement at the same time each day (consistency matters for supplements). Use the app to photograph your progress monthly in a private journal to track visible changes over time. Record any side effects or unusual symptoms immediately.
- Create a monthly check-in where you review your symptom scores and note any patterns. After 8-12 weeks, compare your starting severity score to your current score to see if the supplement is working. Share this data with your doctor at your next visit to inform decisions about continuing or adjusting your approach.
This article summarizes research findings and is not medical advice. Pumpkin seed oil supplementation may not be appropriate for everyone, especially men with serious health conditions, those taking hormone-related medications, or those with pumpkin allergies. The study described is a single research article; larger, more rigorous studies are needed to confirm these findings. Before starting any supplement for gynecomastia, consult with a healthcare provider to rule out underlying medical causes, ensure the supplement won’t interact with your medications, and determine the right treatment approach for your specific situation. This information is for educational purposes only and should not replace professional medical evaluation and treatment.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.