❤️‍🔥 ED & Low Libido

What this panel can settle, and by what logic

The list is arranged around a fact most buyers do not arrive with: erectile dysfunction is usually a vascular symptom with a hormonal differential, not a hormone problem with a vascular footnote. The vascular half is the larger one.

1. ApoB (Apolipoprotein B) with hs-CRP (High-Sensitivity C-Reactive Protein) and HbA1c (Hemoglobin A1c) is the half that matters. Erectile dysfunction and cardiovascular disease share endothelial dysfunction as a cause, and because the penile arteries are smaller than the coronaries the same degree of arterial disease limits flow there first — which is why ED often precedes cardiovascular disease by 2 to 5 years De Leonardis 2022. ApoB reflected residual risk better than LDL cholesterol across 13,015 statin-treated adults over a median of 8 years Johannesen 2021, so it is the marker that decides what the finding means.
2. Fasting Insulin beside HbA1c (Hemoglobin A1c) moves the clock earlier. HbA1c integrates 8 to 12 weeks and insulin rises years before it Krhač 2019. In a man of 40 with a normal glucose, the insulin is where the vascular story actually starts.
3. Total Testosterone with SHBG (Sex Hormone-Binding Globulin) is a differential, not an answer. Two men at 500 ng/dL with SHBG of 20 and 60 nmol/L do not have the same free fraction, and a total reported without SHBG cannot be converted into anything usable Livingston 2023.
4. Prolactin costs $9 and is occasionally the entire answer. A prolactin-secreting adenoma presents with lost libido long before anything else and is treated medically Petersenn 2023. Around a fifth of raised results are macroprolactin, which the assay counts and the body cannot use Sharma 2021.

What it cannot settle, and what would

It measures vascular risk and cannot see a vessel, which is the gap this panel is most often bought to close. ApoB, hs-CRP, HbA1c and Homocysteine are risk factors. Endothelial dysfunction and flow-limiting stenosis are the lesions, and all four markers are blind to them De Leonardis 2022. A clean cardiovascular block does not exclude arteriogenic ED; what images it is a coronary calcium score or a penile duplex ultrasound. The review's own recommendation is that a man presenting with ED is investigated for cardiovascular disease even with no cardiac symptoms at all De Leonardis 2022.

It cannot see the commonest non-vascular causes, because they have no marker. SSRIs and other antidepressants, beta blockers, finasteride, alcohol, poor sleep, performance anxiety and relationship context all produce this presentation De Leonardis 2022. The most useful discriminator available is free: preserved morning and nocturnal erections point away from an arterial cause and towards the ones on this list that blood does not reach.

A normal testosterone does not exclude it as a contributor, and a low one does not make it the cause. Testosterone deficiency is diagnosed on symptoms plus two low morning values Hackett 2023, and this panel is one draw with real within-subject variation behind it Itkonen 2024. A single 340 ng/dL in a man with ED is a prompt for a second morning sample, not a prescription.

And it cannot tell you whether a PDE5 inhibitor will work, which is what a large share of buyers actually want to know. That is a clinical trial of one, and it is worth running alongside the vascular work rather than instead of it De Leonardis 2022.

Draw conditions that decide whether the money is wasted

Four conditions. The first two decide whether the hormone half is readable and the third decides whether the vascular half is.

1. 7 to 10am, fasted. Testosterone peaks in the early morning and an afternoon draw is how a healthy man gets read into a diagnosis Livingston 2023. The fast is for the triglycerides and the insulin: a non-fasted Fasting Insulin is not a fasting insulin and the resistance calculation it feeds is then meaningless Krhač 2019.
2. Prolactin rested for 20 to 30 minutes. Stress, a difficult venepuncture and sleep all raise it, and a high result sends people toward imaging when the correct next step is macroprolactin screening Sharma 2021.
3. Not within 2 weeks of an illness. hs-CRP (High-Sensitivity C-Reactive Protein) is what this panel uses to decide whether the vascular picture is inflammatory, and any infection lifts it into the range that would otherwise mean something De Leonardis 2022.
4. No biotin for 3 days, and list every medication on the form. Prolactin and TSH are streptavidin-based on the common analyzers, so a hair supplement at 5,000 mcg moves several markers at once Li 2020. Finasteride, SSRIs and beta blockers change the answer rather than the numbers, and nobody can allow for what they were not told.

How you would know it answered your question, and what each pattern means next

Five patterns, and the most valuable one is the pattern where the hormones are fine.

• Normal testosterone with a raised ApoB (Apolipoprotein B), HbA1c (Hemoglobin A1c) or hs-CRP (High-Sensitivity C-Reactive Protein): this is a vascular result and the most useful thing this panel produces. It goes to a clinician for cardiovascular assessment rather than to a PDE5 prescription alone, and the 2 to 5 year lead time is the entire reason to act now De Leonardis 2022. Retest ApoB 12 weeks after any change, which is when lipoprotein concentrations have reached a new steady state Johannesen 2021.
• Raised Fasting Insulin with a normal HbA1c (Hemoglobin A1c): the early form of the same finding Krhač 2019. Retest HbA1c at 12 weeks, because it averages the lifespan of a red cell, and repeat the insulin with it.
• Raised Prolactin: repeat it rested, screen for macroprolactin Sharma 2021, and only then consider imaging Petersenn 2023.
• Total Testosterone under 300 ng/dL: a second morning draw before anything else happens Itkonen 2024 Hackett 2023.
• Everything normal: common, and it moves the question rather than closing it. Preserved nocturnal erections point at the causes on no requisition; absent ones point back at the arteries and at a duplex study De Leonardis 2022.

Sources read for these sections

• De Leonardis F, et al. Endothelial Dysfunction, Erectile Deficit and Cardiovascular Disease: An Overview of the Pathogenetic Links. Biomedicines 2022 · PMID 36009395
• Johannesen CDL, et al. Apolipoprotein B and Non-HDL Cholesterol Better Reflect Residual Risk Than LDL Cholesterol in Statin-Treated Patients. Journal of the American College of Cardiology 2021 · PMID 33736827
• Krhač M, Lovrenčić MV. Update on biomarkers of glycemic control. World Journal of Diabetes 2019 · PMID 30697366
• Livingston M, et al. Adult Male Hypogonadism: A Laboratory Medicine Perspective on Its Diagnosis and Management. Diagnostics (Basel) 2023 · PMID 38132234
• Petersenn S, et al. Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement. Nature Reviews Endocrinology 2023 · PMID 37670148
• Sharma LK, et al. Prevalence of Macroprolactinemia in People Detected to Have Hyperprolactinemia. Journal of Laboratory Physicians 2021 · PMID 34975255
• Hackett G, et al. The British Society for Sexual Medicine Guidelines on Male Adult Testosterone Deficiency, with Statements for Practice. World Journal of Men's Health 2023 · PMID 36876744
• Itkonen O, et al. The European biological variation study (EuBIVAS): Biological variation data for testosterone, follicle stimulating hormone, prolactin, luteinizing hormone and dehydroepiandrosterone sulfate in men. Clinica Chimica Acta 2024 · PMID 38341016
• Li D, Ferguson A, Cervinski MA, Lynch KL, Kyle PB. AACC Guidance Document on Biotin Interference in Laboratory Tests. J Appl Lab Med 2020 · PMID 32445355