Sildenafil for Erectile Dysfunction: Pivotal Study
New England Journal of Medicine (1998)
Goldstein et al. demonstrated sildenafil significantly improved erectile function across all severity levels vs placebo.
How it works
Marek's Guided Optimization® Program combines advanced lab testing, a dedicated health coach and medical provider, and a personalized treatment plan, all built around your data.
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The process
1
Start your assessment
Complete your 45-min intake assessment
2
Get your labs drawn
4,000 partnered lab locations nationwide
3
Review with your coach
Screen-by-screen lab review
4
Receive your protocol
Treatment delivered to your door
Why Marek
The only program pairing you with a dedicated health coach and medical provider, built on precision diagnostics, with no subscription required.
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Meet our co-founder
Derek
Co-Founder · MPMD Podcast
"Over time, I found it incredibly difficult to get medical oversight for myself and my family that reflected the latest research, and that was preventative. That's why I started Marek Health."
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What we test
Every client's lab panel is hand-selected from 1,000+ available biomarkers, built around their specific goals.
Panel categories
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Treatments
700+ medical provider-prescribed therapies built from your labs. Browse by category or explore the full formulary.
Sildenafil
Oral tablet (20mg, 100mg)Available in all 50 statesMarketing purposes only. Actual medications, if prescribed, are dispensed by a licensed pharmacy.
sexual health
SildenafilSildenafil
The original PDE5 inhibitor with a 4 to 5 hour duration of action, providing on-demand erectile function support. Also FDA-approved for pulmonary arterial hypertension (Revatio).
Rapid onset (30 to 60 minutes)
Well-established efficacy and safety
Available in low-dose for PAH
Generic, cost-effective
No commitment · HSA/FSA eligibleNo commitment · HSA/FSA eligible
How it works
Mechanism of action
Selectively inhibits PDE5, enhancing NO-mediated cGMP signaling in penile and pulmonary vascular smooth muscle, causing vasodilation.
The baseline panel.
Every Marek client receives this baseline panel before a provider review. Your provider may add additional biomarkers based on your health history, symptoms, and goals, pulling from 1,000+ available markers. See more biomarkers →
Hormone Profile
12 markers
Sex hormones
- Total TestosteroneLC/MS
- Free TestosteroneEquilibrium Dialysis
- Estradiol, Sensitive / UltrasensitiveLC/MS
- Sex Hormone Binding Globulin (SHBG)
- ProgesteroneLC/MSFemale panel
- Prolactin
- Luteinizing Hormone (LH)
- Follicle-Stimulating Hormone (FSH)
- hCG, Total, QuantitativeFemale panel, pre-menopause
Adrenals & neurosteroids
- Cortisol
- DHEA-S
Growth hormone / IGF-1
- Insulin-Like Growth Factor I (IGF-1)
Thyroid Status
3 markers
Thyroid hormones
- Thyroid Stimulating Hormone (TSH)
- Free T4
- Free T3
Heart Health
9 markers
Cardiovascular health
- Total Cholesterol
- HDL Cholesterol
- LDL Cholesterol
- LDL:HDL Ratio
- VLDL Cholesterol
- Triglycerides
- Apolipoprotein-B (ApoB)
- C-Reactive Protein, High Sensitivity (hsCRP)
- Lipoprotein(a) (Lp(a))
Metabolism
3 markers
Insulin sensitivity
- Blood Glucose
- Fasting Insulin
- HbA1c
Organ Function
26 markers
Liver & pancreas
- AST
- ALT
- Bilirubin, Total
- γ-Glutamyl Transferase (GGT)
Kidney function
- BUN
- Creatinine w/ eGFR
Comprehensive Metabolic Panel (CMP)
- Glucose
- Blood Urea Nitrogen (BUN)
- Creatinine
- eGFR
- BUN/Creatinine Ratio
- Sodium
- Potassium
- Chloride
- Carbon Dioxide, Total
- Calcium
- Protein, Total
- Albumin
- Globulin, Total
- Albumin/Globulin (A/G) Ratio
- Alkaline Phosphatase (ALP)
- AST
- ALT
Prostate health
- Prostate-Specific Antigen (PSA)Male panel
- Free PSAMale panel
- % Free PSAMale panel
Nutrient Status
31 markers
Vitamins & minerals
- Vitamin D, 25-OHD (25-Hydroxy)
- Magnesium, RBC
Iron status
- Iron
- Iron Saturation
- TIBC
- UIBC
- Ferritin
Complete Blood Count (CBC)
- White Blood Count (WBC)
- Red Blood Count (RBC)
- Hemoglobin (Hgb)
- Hematocrit (HCT)
- MCV
- MCH
- MCHC
- Red Cell Distribution Width (RDW)
- Platelets
- Neutrophils
- Neutrophils (Absolute)
- Lymphocytes
- Lymphocytes (Absolute)
- Neutrophil/Lymphocyte Ratio
- Monocytes
- Monocytes (Absolute)
- Eosinophils
- Eosinophils (Absolute)
- Basophils
- Basophils (Absolute)
- Immature Cells
- Immature Granulocytes
- Immature Granulocytes (Absolute)
- NRBC, w/ Reflex for Immature Cells
Clinical evidence
The research behind Sildenafil.
Safety profile
Monitoring & safety information.
Commonly reported side effects
- Headache
- Flushing
- Dyspepsia
- Visual disturbance (blue tinge)
- Nasal congestion
Less common but serious risks
- Hypotension with nitrates
- Priapism (rare)
- NAION (very rare)
- Hearing loss (very rare)
Generally not appropriate for
- Concurrent nitrates
- Severe hepatic impairment
- Recent stroke/MI
Typical monitoring
- Blood pressure
- Visual symptoms
- Erectile function assessment
FAQ
Quick answers.
The original PDE5 inhibitor with a 4 to 5 hour duration of action, providing on-demand erectile function support. Also FDA-approved for pulmonary arterial hypertension (Revatio).
Rapid onset (30 to 60 minutes). Well-established efficacy and safety. Available in low-dose for PAH. Generic, cost-effective.
Common side effects include: headache, flushing, dyspepsia, visual disturbance (blue tinge), nasal congestion. Most side effects are dose-dependent and may resolve with continued use or dose adjustment.
The original PDE5 inhibitor with a 4 to 5 hour duration of action, providing on-demand erectile function support. Also FDA-approved for pulmonary arterial hypertension (Revatio).
Treatments are dependent on licensed clinical prescription. Client costs vary based on individual labs and panel in treatments and services.