Testosterone
Soy and testosterone: does soy lower testosterone in men?
Soy contains plant compounds called phytoestrogens, which has led to fears that it feminises men. Here is what the research shows about soy and testosterone.
In short: Reviews of human clinical studies have found that normal intakes of soy foods do not lower testosterone or raise oestrogen in men. Rare case reports of hormonal effects involved very high intakes. Soy is a good source of plant protein, and moderate amounts of soy foods are considered safe for men.
What are phytoestrogens?
Soy contains isoflavones, plant compounds with a similar structure to oestrogen. They bind weakly to oestrogen receptors and act very differently from human oestrogen.
What the research shows
Testosterone
Meta-analyses of clinical studies found that soy protein and isoflavones had no significant effect on testosterone or free testosterone in men.
Oestrogen
The same reviews found no meaningful change in oestrogen levels with normal intakes.
Breast tissue
Rare case reports describe breast enlargement in men drinking very large amounts of soy milk daily. These are exceptions with extreme intakes. See gynecomastia causes.
Sperm
One observational study linked high soy intake with lower sperm concentration, but other studies found no effect. Evidence is mixed.
Prostate
Population studies in Asia link soy intake with lower prostate cancer risk.
How much soy is fine?
Moderate amounts of whole soy foods, such as one to two servings a day of tofu, soy milk, edamame or tempeh, are considered safe for men.
Soy as protein
Soy is a complete plant protein and a useful alternative to processed meat, supporting heart health.
What really affects testosterone
- Excess body fat
- Poor sleep
- Heavy alcohol use. See beer and testosterone.
- Chronic stress
- Lack of strength training
See how to increase testosterone naturally.
How we can help
A naturopath can review your diet and symptoms and build a natural plan to support healthy hormones.
Why men choose our natural approach
Walk in or consult remotely
Walk in at Buccleuch, Sandton, with parking available, or consult by phone or video from anywhere in South Africa.
Natural and non-surgical
Herbal remedies and practical guidance, with no injections or surgery.
Faster appointments
Enquiries answered 24/7, with same-day appointments often available.
Transparent pricing
Consultations are R2,500, with any remedy costs confirmed before you commit.
Private self-check: 5 quick questions
Answer these honestly before you try anything new or book. They help you describe what is happening and get more from your first consultation.
- Has your interest in sex dropped noticeably over the past year?
- Do you feel tired most days, even after a full night in bed?
- Has your weight around the middle increased?
- Have stress, low mood or poor sleep become more common?
- Have you noticed weaker erections or fewer morning erections?
Two or more yes answers suggest that energy, sleep, stress or weight may be affecting your drive. These are areas where natural, practical support often makes a real difference, and a naturopath can help you work out where to start.
What happens at your first consultation
- Walk in or book online, call +27 10 205 9855 or WhatsApp +27 81 823 1313. In Gauteng, walk in at 199 Vanessa Street, Buccleuch, Sandton, where parking is available. Outside Gauteng, choose a confidential phone or video consultation. Enquiries are answered 24/7.
- Talk privately with a naturopath about your symptoms, health history, lifestyle and goals.
- Receive a personalised natural plan, with any remedy costs confirmed upfront.
- Follow up in person or remotely so your progress is reviewed and your plan adjusted.
Your health and safety
Our naturopaths use natural remedies and lifestyle support, and always check your health history and current medicines first. If anything needs medical attention we tell you honestly and refer you to an appropriately registered medical professional. Avoid unregistered “enhancement” products sold online or at markets, as SAHPRA has warned that some contain hidden ingredients.
Seek urgent medical care for chest pain, an erection lasting more than four hours, sudden weakness or other sudden symptoms.
Consultation price
A consultation is R2,500, in person or remote, and your naturopath confirms any further costs before you go ahead. See our men’s clinic prices for details.
Frequently asked questions
Does soy lower testosterone?
Reviews of human studies found normal soy intake does not lower testosterone in men.
Can soy cause man boobs?
Only rare cases with very high intakes have been reported. Normal amounts are not linked with breast growth.
Is soy milk bad for men?
Moderate soy milk is considered safe for men.
How much soy is safe for men?
One to two servings of whole soy foods a day is considered safe.
How much does a consultation cost?
A consultation is R2,500, and any remedy costs are confirmed with you before you go ahead.
Book your consultation today
Get personalised, natural support from a naturopath. Walk in at our Sandton practice, or book a remote consultation if you live outside Gauteng.
References and further reading
Reviewed by George Mulaudzi, Naturopath. This page is general information and does not replace a personal consultation. If you have chest pain, sudden symptoms or a medical emergency, seek urgent medical care.
