💊 On the Pill (or Coming Off It)

What this panel can settle, and by what logic

Read this panel as a measurement of your contraceptive rather than of you, and it becomes genuinely useful. Three findings.

1. SHBG (Sex Hormone-Binding Globulin) with Total Testosterone and Free Testosterone shows the size of the effect in YOUR circulation. The direction depends on the method, and it is not small. In a randomized comparison of three non-oral methods, SHBG at 6 months was 23.35 nmol/L on the levonorgestrel implant against 49.1 nmol/L on a copper coil — a mean difference of 50.04%, p < 0.001 — with free testosterone correspondingly higher on the implant Hofmeyr 2024. Oral ethinylestradiol pushes SHBG the other way. So ‘the pill lowers free testosterone’ is a statement about one class of product, and this panel tells you which side of it you are on.
2. LH & FSH with Estradiol, Sensitive (LC/MS-MS) shows how hard the axis is being held down, and by how much. Suppression is formulation-dependent: in a head-to-head trial, the estradiol valerate product cut FSH by 27% (95% CI −51 to −3) while the ethinylestradiol product cut it by 64% (95% CI −78 to −51, P = 0.04) Haverinen 2022. Two pills, the same category, more than a twofold difference.
3. Vitamin B12, Folate, Serum, Magnesium, RBC and Zinc, Plasma are the depletion half, and the two mineral markers were chosen for a reason: red cell magnesium reflects tissue status where serum does not Ab Rahim 2023, and plasma zinc is interpretable only under strict collection conditions Ceballos-Rasgado 2024.

What it cannot settle, and what would

It cannot give you a baseline while you are still taking it. This is the structural problem with the product and it deserves stating first. Combined contraceptives suppress the gonadotropins, supply exogenous estrogen and change the binding protein, so LH & FSH, Estradiol, Sensitive (LC/MS-MS) and Free Testosterone describe the drug Haverinen 2022. Even androgen output measured across whole cycles reflects it: in elite athletes tracked with near-daily sampling, urinary testosterone averaged 2.55 ng/mL on combined oral contraceptives against 5.45 ng/mL in naturally cycling athletes, p < 0.001 Nolte 2026. If the question is what your own axis does, this panel answers it only after you stop.

It cannot tell you why your periods have not come back. Post-pill amenorrhea is usually the condition the pill was masking — polycystic ovary syndrome, hypothalamic amenorrhea, hyperprolactinemia — rather than damage the pill caused. A raised Prolactin here needs a rested repeat and a macroprolactin screen, because roughly a fifth of hyperprolactinemia is an inactive antibody-bound complex needing no treatment at all Sharma 2021.

It carries no thyroid marker, and that is a real omission for this reader. Estrogen-containing oral contraceptives have been examined for an association with hypothyroidism in their own right Alkahlout 2025, and low mood, fatigue and low libido — the three symptoms that bring people to this page — are also how hypothyroidism presents. A $9 TSH would close that gap.

And a free testosterone at female concentrations is at the edge of what a direct assay can do. The laboratory position statement on measuring sex steroids recommends mass spectrometry at low concentrations for exactly this reason Casals 2023, so a small difference between two reports may be the analyzer rather than the pill.

Draw conditions that decide whether the money is wasted

There is no cycle day on hormonal contraception, so the timing question becomes a different one: where you are in the pack, or how long since you stopped.

1. Still on a combined pill: draw mid-pack, not in the hormone-free week. The withdrawal interval lets the axis begin to rebound, so an LH & FSH taken in those seven days sits between two states and represents neither Haverinen 2022. Write the product name on the form; the difference between formulations is larger than most of the differences you are looking for.
2. On an implant, an injection or a coil: any day, and say which one. These have no pack and no hormone-free interval, and their effects on SHBG and free testosterone run in different directions from each other Hofmeyr 2024. A result read against a combined-pill expectation will be read wrongly.
3. Coming off: wait 3 months, then draw days 2 to 5 of a real bleed. SHBG is a hepatic protein and it moves over months rather than weeks, and gonadotropin recovery takes cycles. A panel drawn 3 weeks after the last pill measures the exit, not the destination Haverinen 2022.
4. Zinc, Plasma is the fussiest tube on the list. Zinc assessment is sensitive to fasting state, time of day, recent meals and hemolysis, which is why the methodological reviews specify collection conditions rather than just a reference interval Ceballos-Rasgado 2024. Morning, fasted, and a clean draw — otherwise the number reports the phlebotomy.

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

Five patterns, and three of them have an interval set by how slowly a liver protein moves.

• Very high SHBG (Sex Hormone-Binding Globulin) with a low Free Testosterone, still on a combined pill: this is the expected result rather than a finding, and it is a plausible mechanism for low desire. If you switch or stop, retest at 3 to 6 months; SHBG does not fall on a weekly timescale Haverinen 2022.
• Low SHBG (Sex Hormone-Binding Globulin) with a high free testosterone on an implant: also expected, and the reason acne and hirsutism can appear on a progestin-only method Hofmeyr 2024. Worth knowing before you conclude you have developed PCOS.
• Off the pill 3 months, LH & FSH and Estradiol, Sensitive (LC/MS-MS) still flat with no bleed: the axis has not restarted and the question is now what was underneath. Add TSH (Thyroid-Stimulating Hormone) and take a rested Prolactin to a clinician Sharma 2021.
• Low Vitamin B12 on a long-term user: replace and recheck the functional marker rather than serum B12, which tracks the last dose instead of the store Harrington 2024. Do this before conceiving rather than after, alongside the Folate, Serum.
• Everything unremarkable and the symptoms unchanged: a legitimate outcome. The next step is a thyroid marker and a clinician, not a repeat of the same nine tests, and a panel drawn while the exposure is still in place cannot become more informative by being repeated Nolte 2026.

Sources read for these sections

• Haverinen A, et al. Estradiol Valerate vs Ethinylestradiol in Combined Oral Contraceptives: Effects on the Pituitary-Ovarian Axis. Journal of Clinical Endocrinology and Metabolism 2022 · PMID 35279718
• Hofmeyr GJ, et al. Effects of depot medroxyprogesterone acetate, the copper IUD and the levonorgestrel implant on testosterone, sex hormone binding globulin and free testosterone levels: ancillary study of the ECHO randomized clinical trial. BMC Women's Health 2024 · PMID 38459552
• Nolte J, et al. Tracking androgens in female elite athletes: menstrual cycle and hormonal contraceptive effects. BMC Women's Health 2026 · PMID 41826936
• Alkahlout L, et al. The Association Between Estrogen-Containing Oral Contraceptive Pills and Hypothyroidism. International Journal of Endocrinology 2025 · PMID 40135042
• Sharma LK, et al. Prevalence of Macroprolactinemia in People Detected to Have Hyperprolactinemia. Journal of Laboratory Physicians 2021 · PMID 34975255
• Casals G, et al. Recommendations for the measurement of sexual steroids in clinical practice. A position statement of SEQCML/SEEN/SEEP. Advances in Laboratory Medicine 2023 · PMID 37359897
• Ceballos-Rasgado M, et al. Methods of Assessment of Zinc Status in Humans: An Updated Review and Meta-analysis. Nutrition Reviews 2024 · PMID 38917458
• Ab Rahim SN, et al. The Laboratory and Clinical Perspectives of Magnesium Imbalance. Cureus 2023 · PMID 38045630
• Harrington DJ. The application and interpretation of laboratory biomarkers for the evaluation of vitamin B12 status. Annals of Clinical Biochemistry 2024 · PMID 39367523