Testosterone
Intermittent fasting and testosterone: what the research says
Intermittent fasting is popular for weight loss, and men often ask how it affects hormones and sexual health. Here is what research shows about intermittent fasting and testosterone.
In short: Studies show intermittent fasting does not reliably raise testosterone, and some trials in lean, active men found a small drop. However, in men with excess weight, the weight loss from fasting can improve testosterone, insulin sensitivity and erections. Fasting suits some men but not others, and very aggressive fasting can lower energy and drive.
What is intermittent fasting?
Intermittent fasting means eating within a time window or limiting food on certain days. Common approaches include:
- 16:8: eating within an eight-hour window each day
- 5:2: eating normally five days a week and much less on two days
Effects on testosterone
- Some studies in lean, physically active young men found time-restricted eating slightly lowered testosterone, without loss of strength.
- In men with obesity, fasting that leads to weight loss tends to improve testosterone, because losing belly fat reduces conversion of testosterone to oestrogen. See high estrogen in men.
- Short-term fasting can briefly raise growth hormone, but this does not mean higher testosterone.
Potential benefits for sexual health
- Weight loss and less belly fat. See weight loss and erectile dysfunction.
- Better insulin sensitivity and blood sugar. See sugar and erectile dysfunction.
- Lower blood pressure in some people.
Possible downsides
- Low energy, irritability and poor sleep if calories are too low.
- Lower libido if fasting is too aggressive or combined with heavy training.
- Overeating in the eating window.
- Not suitable for men with diabetes on certain medicines, a history of eating disorders, or some medical conditions, without advice.
How to fast sensibly
- Start with a 12-hour overnight fast and extend gradually.
- Eat enough protein, vegetables, healthy fats and whole grains in your window.
- Stay hydrated.
- Keep strength training to protect muscle.
- Prioritise sleep.
The bottom line
Intermittent fasting is a tool for weight loss, not a testosterone booster. For men carrying extra weight, it can support better hormones and erections. For lean men, it is unlikely to help testosterone. Read how to increase testosterone naturally.
How we can help
Our naturopaths can help you choose an eating pattern that suits your health, energy and goals.
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 intermittent fasting increase testosterone?
Not reliably. In lean men it may slightly lower testosterone, while weight loss from fasting can improve levels in overweight men.
Is intermittent fasting good for erectile dysfunction?
It may help men with excess weight by improving weight, blood sugar and blood pressure.
Can fasting lower libido?
Aggressive fasting with too few calories can lower energy and drive.
What is the safest way to start fasting?
Begin with a 12-hour overnight fast and extend gradually, eating balanced meals in your window.
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
- Mayo Clinic: Male hypogonadism
- NIDDK: Symptoms and causes of erectile dysfunction
- NCCIH: Using dietary supplements wisely
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.
