If You Knew What PDE5 Inhibitors Actually Did, You’d Be Taking One Already

​​Most people think of PDE5 inhibitors as sex drugs. Viagra, Cialis, Levitra. The assumption has always been the same: you take one before sex and wait.

But that’s just the surface. These compounds were never meant to be confined to that one function.

They were developed to improve blood flow. That’s their core mechanism. And blood flow affects nearly every major system in the body. Brain, muscle, metabolism, hormonal signaling. Even how quickly you recover from training or how mentally sharp you feel by 3 p.m.

Which means they may be far more versatile than people realize. Once you look past the marketing history, the real question is not whether you need help with performance. It’s what better circulation might unlock.

What PDE5 Inhibitors Actually Do

These drugs increase nitric oxide signaling in the vasculature, which relaxes blood vessels and improves circulation. The result is more efficient delivery of oxygen and nutrients to tissue. It’s not just about sex. It’s a system-level shift.

They’re already FDA-approved for several conditions, including:

• Erectile dysfunction
• Pulmonary arterial hypertension
• Benign prostatic hyperplasia (BPH)

But in recent years, researchers have started testing their broader effects. Not just in sick populations, but in healthy people too.

Muscle Pump, Growth, and Recovery

Nitric oxide-driven vasodilation improves the "pump" you feel during training. But there’s more happening behind the scenes.

Studies show that PDE5 inhibitors can double muscle protein synthesis after training, accelerating muscle repair and growth. The impact has been compared to moderate-dose testosterone replacement. They may also improve endothelial function, support better insulin response, and modulate estradiol levels, all of which matter for recovery and composition.1–3

Think Faster, Focus Better

Brain fog isn't always about sleep or stress. Circulation matters here too.

PDE5 inhibitors have been shown to increase blood flow to the prefrontal cortex, brainstem, and areas associated with memory and attention. In trials involving individuals with mild cognitive decline, users showed faster mental processing and improved short-term memory.4

One study also suggested that patients with BPH and ED saw cognitive gains, possibly through vascular support and nitric oxide pathways.5

More Reps, Less Fatigue

Training is one thing. Recovery between sets is another.

In a controlled study, participants using a low-dose PDE5 inhibitor completed significantly more reps before reaching failure. Oxygenation was better. Perceived fatigue was lower. The implication is clear: enhanced microcirculation improves performance, not just tolerance.1

Have Better Sex, With Better Control

This one is obvious, but worth saying clearly.

Combining PDE5 inhibitors like tadalafil and vardenafil can improve erection strength, duration, and reliability. You also get reduced refractory time and a lower likelihood of performance variability.6,7 If timing has ever been an issue, or if on-demand dosing feels too unpredictable, a steady low-dose or hybrid protocol can smooth that out.

Maximus offers all formats:

• Tadalafil for long half-life and baseline support
• Vardenafil for faster onset and cleaner tolerability
• Sildenafil for those who prefer the original gold standard
• Combination therapies for around-the-clock flexibility
• And microdosing options for subtle but consistent effect

It’s not about one drug being best. It’s about what fits you.8

What Makes Maximus Different

Most people have never considered PDE5 inhibitors for brain health or workout performance. And even if they have, the logistics usually make it unappealing. Timing. Side effects. Trial and error.

The Maximus Blood Flow Protocol solves for that with a tailored system:

• Microdosing: Lower, daily doses for smoother effect with fewer side effects
• Single-agent options: Full-dose tadalafil, vardenafil, or sildenafil, for those who prefer one compound or have tolerability constraints
• Stacking strategies: Combine long-acting and fast-acting agents if you want sustained support with flexibility
• Guided titration: Start at the right level for your body and adjust based on actual results, with clinician oversight
• Cost advantage: All the same active ingredients as the brand names, at up to 90 percent lower cost

Some users report feeling the difference within a day or two. Others notice better mental output, steadier energy, and even stronger pumps in the gym by week one.

There’s no need to chase side effects to get the benefits. This protocol gives you access to both performance and tolerability.

Start With the Right Dose

It only takes a few minutes to get started.

Answer a few questions. Share your goals. You’ll be matched with the formulation that fits your biology and your timeline, whether that’s microdosing, full-dose monotherapy, or a targeted stack.

Take the Maximus Quiz to Begin Your Blood Flow Protocol

This isn’t just about better sex or longer workouts. It’s about making your brain and body work a little better, a little more often. That effect builds. Subtly at first. But it compounds.

And that’s the real edge.

Reviewed by:

Gabriel Alizaidy, MD, MS

Starling Krentz, MS

----

Disclaimer: The contents of this article, including, but not limited to, text, graphics, images, and other information, is for information purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. The content is not meant to be complete or exhaustive or to be applicable to any specific individual's medical condition. You should consult a licensed healthcare professional before starting any health protocol and seek the advice of your physician or other medical professional if you have questions or concerns about a medical condition. Always talk to your doctor about the risks and benefits of any treatment. Never disregard or delay seeking professional medical advice or treatment because of something you have read on this site. Maximus does not recommend, endorse, or make any representation about the efficacy, appropriateness, or suitability of any specific test, products, procedures, treatments, services, opinions, healthcare providers or other information contained herein. Maximus is not responsible for, nor will they bear any liability for, the content provided herein or any actions or outcomes resulting from or related to its use.

----

References

1. Sheffield-Moore M, Dillon EL, Casperson SL, et al. A randomized pilot study of monthly cycled testosterone replacement or a daily PDE5 inhibitor for older men with low testosterone. Clin Transl Sci. 2013;6(5):306-312. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4076819/
2. Aversa A, Bruzziches R, Spera G, La Pera G. Efficacy of daily tadalafil versus alternate-day sildenafil in men with erectile dysfunction and low testosterone levels. Endocrine. 2017;55(1):243-250. https://pubmed.ncbi.nlm.nih.gov/28133708/
3. McGlory C, Gorissen SHM, Kamal M, et al. No differences in muscle protein synthesis between a high-dose and standard-dose protein feeding during recovery from resistance exercise. J Appl Physiol (1985). 2017;122(3):541-553. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5401959/
4. Urios A, Ortega M, Díez C, et al. Sildenafil improves cognitive function in patients with cirrhosis and minimal hepatic encephalopathy. Sci Rep. 2019;9(1):14827. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6863868/
5. Schultheiss D, Truss MC, Stief CG, Jonas U. Sildenafil in the treatment of erectile dysfunction: a review of the literature. World J Urol. 2001;19(1):61-65. https://pubmed.ncbi.nlm.nih.gov/11289570/
6. Cui H, Liu B, Song Z, et al. Efficacy and safety of daily tadalafil versus on-demand tadalafil in men with erectile dysfunction: A systematic review and meta-analysis. Andrologia. 2015;47(5):499-508. https://pubmed.ncbi.nlm.nih.gov/24387078/
7. Gökçe A, Oktar T, Bulut S, et al. Efficacy of on-demand vardenafil for erectile dysfunction and urinary symptoms in men with lower urinary tract symptoms. BJU Int. 2011;108(2):293-297. https://pubmed.ncbi.nlm.nih.gov/21929518/
8. Althof SE, Eid JF, Talakoub L, et al. Through the eyes of women: the sexual and psychological impact of erectile dysfunction treatment. Urology. 2006;68(6 Suppl):110-114. https://pubmed.ncbi.nlm.nih.gov/16979701/