Best ED Treatment: Comparing Pills, Injections, and Peptides

More Than Half of Men Over 40 Deal With ED — But Most Never Get a Complete Evaluation

Erectile dysfunction is not rare, and it is not something that only affects older men. The Massachusetts Male Aging Study — one of the largest and most cited studies on male sexual health — found that 52 percent of men between 40 and 70 experience some degree of erectile dysfunction (Feldman et al., 1994). That includes mild, moderate, and complete ED. The prevalence increases with age, but it begins far earlier than most men expect.

What most men receive when they bring up ED is a quick prescription. One pill. One mechanism. One hope that it works. And for many men, it does — at least initially. But for a significant number, that single approach either stops working over time or never delivers the results they expected.

The reason is straightforward: erectile dysfunction has multiple potential causes, and a single medication addresses only one of them. At Rewind Anti-Aging of Miami, we approach ED treatment as a system — evaluating hormones, blood flow, nerve function, and desire as interconnected components. The best ED treatment is not a single drug. It is the right combination of interventions matched to your specific physiology.

This guide walks you through every major treatment category we offer, explains how each works, and helps you understand which approach — or combination of approaches — is most likely to restore full sexual function.

Category One: Oral PDE5 Inhibitors

PDE5 inhibitors remain the most commonly prescribed class of ED medication worldwide. They include sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra). At Rewind, the two most frequently prescribed are sildenafil and tadalafil.

How They Work

During sexual arousal, nitric oxide is released in the erectile tissue of the penis. This triggers production of cyclic guanosine monophosphate (cGMP), which relaxes smooth muscle and allows blood to flow into the erectile chambers. An enzyme called phosphodiesterase type 5 (PDE5) breaks down cGMP and terminates this process.

In men with ED, either insufficient cGMP is produced or PDE5 degrades it too quickly. PDE5 inhibitors block this enzyme, allowing cGMP to accumulate and the erection process to complete naturally. They do not create an erection on their own — sexual stimulation is still required.

The landmark clinical trial by Goldstein et al. (1998) demonstrated that sildenafil significantly improved erectile function across a broad range of ED etiologies, establishing PDE5 inhibitors as a viable first-line treatment. Subsequent research by Brock et al. (2002) showed that tadalafil offered a similar efficacy profile with a dramatically longer duration of action — up to 36 hours compared to sildenafil’s 4 to 6 hours.

Sildenafil vs Tadalafil: Which One?

This is one of the most common questions we hear, and we have written a detailed breakdown in our guide to Cialis vs Viagra. The short version:

Sildenafil works within 30 to 60 minutes, lasts 4 to 6 hours, and is best for men who prefer a shorter window and fast onset. It is affected by high-fat meals, which can delay absorption.

Tadalafil takes 30 minutes to 2 hours for onset but lasts up to 36 hours. It is unaffected by food and is available in a daily low-dose option (2.5 to 5 mg) that provides continuous readiness without planning around intimacy. Daily tadalafil also offers benefits for prostate and urinary health.

For men with frequent sexual activity or who value spontaneity, tadalafil is typically the better fit. For men with less frequent encounters who prefer fast, predictable onset, sildenafil is often preferred. Neither is objectively superior — the right choice depends on lifestyle and physiology.

Success Rates and Limitations

PDE5 inhibitors are effective for approximately 60 to 80 percent of men with ED. That is a strong success rate, but it means 20 to 40 percent of men either do not respond adequately or experience side effects that limit use.

Common reasons for PDE5 inhibitor failure include low testosterone (which reduces nitric oxide production — the very molecule these drugs depend on), severe vascular disease, nerve damage from surgery or diabetes, psychological factors that override the pharmacological effect, and incorrect dosing or timing.

When a man tells us that Viagra or Cialis “stopped working” or never worked well, the answer is rarely a higher dose. It is a more thorough evaluation of what is actually causing the dysfunction.

Category Two: Penile Injection Therapy

For men who do not respond to oral medications — or who need a more reliable and potent option — penile injection therapy represents the next tier of treatment. The most common formulation is Trimix, a combination of three vasodilating agents: papaverine, phentolamine, and prostaglandin E1 (alprostadil).

How Injections Work Differently

The critical difference between injection therapy and oral PDE5 inhibitors is the pathway. PDE5 inhibitors work indirectly — they rely on the nerve pathway being intact to generate nitric oxide, which then triggers the downstream process they facilitate. If the nerve pathway is damaged or the hormonal environment is insufficient, PDE5 inhibitors have limited substrate to work with.

Penile injections bypass the nerve pathway entirely. The medication is injected directly into the erectile tissue (the corpora cavernosa), where it acts directly on smooth muscle cells to produce relaxation and blood engorgement. This means injections work even when nerve damage is present — after prostate surgery, in men with diabetic neuropathy, or in cases of severe vascular compromise.

Efficacy

The efficacy of Trimix injections exceeds 90 percent across published studies and clinical experience. This makes it the single most reliable ED treatment available short of a surgical implant. For men who have failed oral medications, injection therapy is not a last resort — it is the intervention most likely to work.

The Self-Injection Reality

The idea of injecting the penis understandably gives most men pause. It is the single biggest barrier to adoption of this therapy. Here is the reality:

The needle used is extremely small — typically a 29 or 30-gauge insulin syringe. Most men describe the injection as a minor pinch, comparable to a finger prick blood sugar test. The injection itself takes seconds.

At Rewind, every patient who starts injection therapy receives in-office training and titration. Your first injection is administered by a clinician who determines the correct dose — the amount that produces a firm erection lasting 30 to 60 minutes without exceeding safe limits. You then practice self-injection under supervision until you are comfortable.

The most commonly reported side effects are minor bruising at the injection site and, rarely, priapism — an erection lasting more than 4 hours. Priapism is a medical concern, which is why dose titration is performed carefully under clinical supervision. With proper dosing, priapism rates are very low.

Who Benefits Most From Injection Therapy

Injection therapy is particularly effective for men who have not responded to PDE5 inhibitors, men who have undergone radical prostatectomy or pelvic surgery, men with diabetic neuropathy affecting erectile nerves, men with severe vascular ED, and men who want the highest possible reliability for sexual performance.

You can learn more about the specifics of this therapy in our detailed guide on Trimix penile injection therapy.

Category Three: Peptide Therapy for Sexual Function

Peptide therapy represents a fundamentally different approach to sexual health. Rather than targeting blood flow (like PDE5 inhibitors) or directly relaxing smooth muscle (like injections), peptides like PT-141 (bremelanotide) work in the central nervous system to enhance sexual desire and arousal at the neurological level.

PT-141: Treating Desire, Not Just Blood Flow

PT-141 is a melanocortin receptor agonist that activates MC4 receptors in the hypothalamus — the brain region that governs sexual desire. When these receptors are activated, the downstream effect is increased sexual motivation, arousal, and responsiveness to sexual stimuli.

This mechanism is important because a significant number of men with ED do not have a blood flow problem. They have a desire problem. The arousal signal that initiates the entire erectile cascade is weak or absent. PDE5 inhibitors cannot address this because they operate downstream of desire — they improve blood flow but do not create the motivation to engage sexually.

PT-141 fills this gap. It can be used alone for men whose primary issue is reduced desire, or in combination with PDE5 inhibitors for men who need both enhanced desire and improved blood flow. The combination approach — addressing the brain and the vasculature simultaneously — often produces results that neither intervention achieves independently.

How PT-141 Is Administered

PT-141 is administered via subcutaneous injection approximately 30 to 60 minutes before sexual activity. Effects can last 6 to 12 hours, with some men reporting residual enhancement of desire for up to 24 to 72 hours. It is not intended for daily use — most protocols recommend no more than 8 doses per month.

The most common side effect is nausea, which is usually mild and temporary. Starting with a lower dose and eating beforehand can minimize this effect.

Custom Compound Medications

One of the advantages of working with a clinic like Rewind that partners with compounding pharmacies is access to custom formulations that are not available at standard pharmacies.

Sildenafil + Oxytocin

Oxytocin is often called the “bonding hormone.” It plays a role in emotional connection, trust, and intimacy. A compound combining sildenafil (for blood flow) with oxytocin (for emotional and physiological arousal) addresses both the mechanical and relational aspects of sexual function. Some men report not just improved erections but a deeper sense of connection during intimacy.

Tadalafil + Sermorelin

Sermorelin is a growth hormone-releasing peptide that supports overall vitality, recovery, and hormonal balance. Combining it with tadalafil in a single formulation provides both acute ED support and longer-term physiological optimization. This combination is particularly relevant for men over 40 who are experiencing age-related declines across multiple systems.

These custom compounds represent the kind of individualized approach that distinguishes a specialized clinic from a standard prescription model.

The Testosterone Connection

No discussion of ED treatment is complete without addressing testosterone. As we cover in detail in our guide to testosterone and libido, testosterone is foundational to every aspect of erectile function.

Testosterone maintains the smooth muscle and structural integrity of the corpora cavernosa. It regulates nitric oxide synthase — the enzyme that produces the nitric oxide that PDE5 inhibitors depend on. It drives libido, which initiates the arousal cascade. And it influences mood, confidence, and energy — psychological factors that directly affect sexual performance.

The Massachusetts Male Aging Study found that low testosterone was independently associated with increased risk of erectile dysfunction, even after controlling for age and other comorbidities (Feldman et al., 1994). This finding has been replicated repeatedly in subsequent research.

When testosterone is low, ED medications of every type underperform. PDE5 inhibitors have less nitric oxide to work with. The arousal signal that triggers the process is weaker. The structural tissue is less responsive. Optimizing testosterone to evidence-based ranges does not just improve libido — it creates the hormonal environment in which every other ED treatment works better.

At Rewind, testosterone therapy is frequently the foundation of an ED treatment protocol, with PDE5 inhibitors, injection therapy, or PT-141 layered on top as needed.

ED as a Cardiovascular Warning Sign

This is the part of the conversation most providers skip, and it may be the most important.

Erectile dysfunction and cardiovascular disease share the same underlying pathology: endothelial dysfunction and atherosclerosis. The blood vessels that supply the penis are smaller in diameter than the coronary arteries. This means that when atherosclerotic plaque begins to accumulate, the penile arteries are affected first — often years before the coronary arteries show symptoms.

Research has consistently demonstrated that ED is an independent predictor of future cardiovascular events. Men who present with ED have a significantly elevated risk of heart attack, stroke, and cardiovascular death over the following 5 to 10 years.

This is why treating ED as purely a sexual health issue is medically incomplete. When a man presents with erectile dysfunction, it is an opportunity — and arguably an obligation — to evaluate cardiovascular risk factors including lipid panels, blood pressure, fasting glucose, inflammatory markers, and family history.

At Rewind, every ED evaluation includes a cardiovascular risk assessment. We are not just treating an erection problem. We are evaluating a potential early warning system for the most common cause of death in men.

When to Use Which Treatment

Making sense of all these options comes down to matching the treatment to the cause:

If the primary issue is blood flow and the nerve pathway is intact: Start with oral PDE5 inhibitors — sildenafil or tadalafil depending on lifestyle preferences. This is the first-line approach for most men with mild to moderate vascular ED.

If PDE5 inhibitors are ineffective or contraindicated: Move to penile injection therapy with Trimix. This is not a failure — it is a progression to a more direct and reliable intervention that works through a different mechanism.

If the primary issue is desire, not blood flow: PT-141 addresses the arousal and desire components that blood flow medications cannot. It can be used alone or in combination with PDE5 inhibitors.

If testosterone is low: Hormone optimization should be the foundation of any ED protocol. Many men find that their ED resolves with testosterone therapy alone, without additional medications. Those who still need support from PDE5 inhibitors or other treatments get dramatically better results when testosterone is in the optimal range.

If the cause is multifactorial: A combination approach — testosterone optimization as the base, a PDE5 inhibitor or injection therapy for blood flow, and PT-141 for desire — addresses erectile dysfunction from every relevant angle. This is the approach that produces the most comprehensive and lasting results.

What to Expect at Your First Visit

If you are considering ED treatment at Rewind, here is what the process looks like:

Comprehensive lab work. Before any treatment is prescribed, we draw labs that include total and free testosterone, estradiol, SHBG, prolactin, PSA, complete metabolic panel, lipid panel, thyroid markers, and other relevant biomarkers. This tells us not just what is happening with your hormones but whether cardiovascular, metabolic, or thyroid factors are contributing.

Clinical consultation. You meet with a provider who reviews your labs, medical history, medications, lifestyle, and specific symptoms. This is not a 5-minute prescription visit. It is a thorough clinical discussion designed to identify every factor contributing to your ED.

Individualized treatment plan. Based on the data, your provider recommends a protocol tailored to your physiology. This might include testosterone optimization, a PDE5 inhibitor, injection therapy, PT-141, custom compounds, or a combination approach. The plan is specific to you.

Ongoing monitoring. Follow-up labs and consultations ensure that your protocol is producing the expected results and that no adjustments are needed. Sexual health is dynamic, and your treatment should evolve as your body responds.

The Right Treatment Exists — You Just Need the Right Evaluation

Erectile dysfunction is among the most treatable conditions in medicine. With the range of options available today — from oral medications to injection therapy to peptides to hormone optimization — there is a solution for virtually every man. The challenge is not the availability of treatments. It is the availability of thorough evaluations that match the right treatment to the right cause.

If you have been handed a prescription without lab work, or if you have tried a medication that did not deliver the results you expected, the issue is likely not that ED treatment does not work. It is that the right treatment has not been identified for your specific situation.

Related Articles

• Cialis vs Viagra: Which ED Medication Is Right for You?
• Testosterone and Libido: How Low T Affects Your Sex Drive
• PT-141 for Sexual Health: How It Works

References

1. Feldman, H. A., Goldstein, I., Hatzichristou, D. G., Krane, R. J., & McKinlay, J. B. (1994). Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. Journal of Urology, 151(1), 54-61. PMID: 8254833
2. Goldstein, I., Lue, T. F., Padma-Nathan, H., Rosen, R. C., Steers, W. D., & Wicker, P. A. (1998). Oral sildenafil in the treatment of erectile dysfunction. New England Journal of Medicine, 338(20), 1397-1404. PMID: 9578024
3. Brock, G. B., McMahon, C. G., Chen, K. K., Costigan, T., Shen, W., Watkins, V., … & Whitaker, S. (2002). Efficacy and safety of tadalafil for the treatment of erectile dysfunction: results of integrated analyses. Journal of Urology, 168(4), 1332-1336. PMID: 12352799

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Struggling with erectile dysfunction? Rewind Anti-Aging of Miami offers comprehensive ED treatment that goes beyond a single prescription — evaluating hormones, blood flow, and desire to build a protocol tailored to your physiology. See how we design your treatment plan, view real patient results, or schedule your consultation today.