Reviewed by George Mulaudzi, Naturopath   |  Last updated: 25 June 2026

The most effective pills to increase blood flow to penis are prescription PDE5 inhibitors: sildenafil, tadalafil, avanafil, and vardenafil. They are well-studied, fast-acting, and in South Africa they are Schedule 4 medicines available only through a registered medical prescriber. This guide covers how they work, how they compare, who should not take them, what the natural alternatives are, and how to get a safe, legitimate prescription rather than an unregulated one.

A note on scope: Sandton Men’s Clinic is a naturopathic practice. It does not prescribe or dispense Schedule 4 medication such as sildenafil, and does not provide testosterone replacement therapy. Where prescription treatment is appropriate, the clinic’s role is assessment and referral to a registered medical doctor, alongside natural and lifestyle-based support it can offer directly.

How These Pills Actually Work

An erection depends on a chain of events: sexual stimulation triggers nitric oxide release, which raises cGMP levels, which relaxes penile arterial smooth muscle so blood can flow in and stay trapped. The enzyme PDE5 normally breaks cGMP back down, ending the erection. PDE5 inhibitors work by blocking that enzyme, keeping cGMP elevated for longer. They do not create arousal or erections on their own; sexual stimulation still has to start the process.

The Four PDE5 Inhibitors Compared

All four work the same way but differ in onset, duration, and how much food affects them:

• Sildenafil (Viagra): onset 30 to 60 minutes, lasts 4 to 6 hours. Best taken on an empty stomach; a heavy meal delays absorption significantly.
• Tadalafil (Cialis): onset 30 to 60 minutes, lasts up to 36 hours. Least affected by food, and available as a low daily dose for ongoing use.
• Avanafil (Stendra/Spedra): onset 15 to 30 minutes, lasts 4 to 6 hours. The fastest-acting option with fewer food interactions.
• Vardenafil (Levitra): onset 30 to 60 minutes, lasts 4 to 6 hours. Broadly similar to sildenafil.

Which one suits a given man depends on lifestyle, side effect tolerance, and medical history, which is exactly what a proper prescribing consultation is for.

Getting a Legitimate Prescription in South Africa

Sildenafil, tadalafil, avanafil, and vardenafil are all Schedule 4 medicines in South Africa. They require a valid prescription from a registered medical practitioner and cannot legally be sold over the counter or supplied by an online reseller without one.

Sandton Men’s Clinic’s role in this pathway is honest and specific: a naturopathic assessment of your symptoms, health history, and lifestyle factors, followed by referral to a registered medical doctor for prescription where that is the appropriate next step. The clinic does not issue the prescription itself. What it can do directly is help you understand what’s driving your symptoms and support you with natural and lifestyle measures alongside any medical treatment you receive.

Who Should Not Take These Pills Without Medical Clearance

Absolute contraindication: nitrate medication. Combining PDE5 inhibitors with nitrates (glyceryl trinitrate, isosorbide mononitrate or dinitrate, or recreational “poppers”) can cause a dangerous, potentially fatal drop in blood pressure. If you take any nitrate medication for any reason, do not take a PDE5 inhibitor without specialist cardiac assessment first.

Other situations that need medical clearance before use include very low blood pressure, a heart attack or stroke within the last six months, severe liver impairment, certain retinal conditions, and use of alpha-blocker medication for prostate enlargement or blood pressure. Common side effects, when the medication is appropriate, include headache, flushing, nasal congestion, indigestion, and occasionally a temporary blue or green tinge to vision with sildenafil. Chest pain after taking a PDE5 inhibitor is a medical emergency: seek urgent care and tell the treating clinician what you took.

When Pills Alone Don’t Work

A few common reasons: insufficient sexual stimulation, since these medications amplify arousal rather than create it; taking sildenafil after a heavy meal, which delays absorption; a dose that’s too low for the degree of vascular impairment; or an underlying hormonal or psychological driver that medication alone won’t fully resolve. Where vascular disease is more advanced, options like penile injections, vacuum erection devices, or testosterone therapy for confirmed low testosterone may be considered, but these require assessment and prescribing by an appropriately qualified medical practitioner or urologist, not something delivered in-house at a naturopathic clinic. The right response to a pill that isn’t working is a review with a prescriber, not a higher dose taken without guidance or a switch to an unverified product.

Why the Unregulated Market Is Dangerous

SAHPRA, South Africa’s health products regulator, has publicly warned consumers against buying illicit erectile dysfunction products, noting that legitimate medicines such as Viagra require a diagnosis, prescription, and monitoring by a registered practitioner, and that products sold outside proper channels carry real risk: the wrong dose, no active ingredient, or an undisclosed one. For men on nitrate medication, an undisclosed PDE5 inhibitor in a “natural” product is a genuine safety risk. There is no upside to sourcing these medications informally when the same active ingredients are available safely through a legitimate prescription.

Natural Support for Blood Flow

A few ingredients have modest, genuine evidence for supporting the same nitric oxide pathway PDE5 inhibitors act on, though none match their reliability for significant ED: L-arginine and L-citrulline, both nitric oxide precursors with some trial support in mild to moderate cases; Panax ginseng, with modest but fairly consistent evidence across several trials; and vitamin D3, relevant where a deficiency is confirmed, which is common in South African winters. None of these replace a proper assessment, and product quality matters as much as the ingredient itself.

Lifestyle factors build the vascular foundation medication works on top of: regular aerobic exercise, stopping smoking, managing blood pressure and cholesterol, and reducing heavy alcohol use all measurably improve the same pathway. For the fuller picture on vascular health and when it needs medical input, see vascular erectile dysfunction. If you’re still working out whether a prescription pill, a libido issue, or something else is actually the right thing to address, sex tablet for men covers that triage in more depth.

What a Consultation at Sandton Men’s Clinic Offers

A confidential discussion of your symptoms, history, and goals; a review of cardiovascular risk factors and current medication; honest guidance on which natural options have real evidence behind them; and, where prescription treatment is the right next step, referral to a registered medical doctor.

Quick Self-Check

This short check is not a diagnosis. It is a starting point to help you think about what might actually be going on.

Frequently Asked Questions | Pills to Increase Blood Flow To Penis

What pills increase blood flow to the penis?

The evidence-based options are prescription PDE5 inhibitors: sildenafil, tadalafil, avanafil, and vardenafil. They work by maintaining the arterial relaxation that allows blood to fill erectile tissue during sexual stimulation. All require a prescription in South Africa.

Can Sandton Men’s Clinic prescribe these pills directly?

No. Sandton Men’s Clinic is a naturopathic practice and does not prescribe or dispense Schedule 4 medication such as sildenafil. Where prescription treatment is appropriate, the clinic assesses your situation and refers you to a registered medical doctor, while offering natural and lifestyle-based support directly.

Can I buy erection pills over the counter in South Africa?

No. PDE5 inhibitors are Schedule 4 medicines and require a valid prescription from a registered medical practitioner. They cannot legally be purchased over the counter.

Are online or “natural” erection pills safe?

Exercise real caution. SAHPRA has warned that illicit erectile dysfunction products sold outside proper channels can contain the wrong dose, no active ingredient, or an undisclosed prescription-strength ingredient, which carries real risk, especially for men on nitrate medication.

What happens if I take these pills with heart medication?

If the medication is a nitrate, the combination can cause a dangerous, potentially fatal drop in blood pressure. This is a medical emergency. Speak to your doctor before combining any PDE5 inhibitor with existing heart medication.