Blood Tests for Acne: The Labs That Matter and What They Show

Short answer: there's no single blood test for acne, but a handful of labs can show what's driving yours. The ones that matter most are the hormones that control oil (free and total testosterone, SHBG, DHEA-S and the free androgen index), the blood sugar and metabolism markers that can amplify them (HbA1c, average glucose, cholesterol and triglycerides), liver and kidney markers that show how your body handles medications and supplements, and vitamin D. Iron and thyroid are worth adding if you also deal with fatigue, heavy periods or hair shedding. Acne has different drivers in different people, and you can't feel or see any of these from your skin, so the way to know which ones are part of your acne is to test.

What is an acne blood test?

"Acne blood test" usually means a panel of hormone and health markers checked to look for internal drivers of breakouts. It doesn't diagnose acne itself: your skin does that. It shows whether something measurable, like a low SHBG, a high HbA1c or a low vitamin D, might be part of the picture, and that's the piece you can't get from a mirror or a skincare routine.

A routine physical rarely includes these markers. Guidelines focus on treatments, and reviews of hormonal acne point to a hormone workup when there are signs of excess androgens, irregular periods, or acne that doesn't respond to standard treatment (Reynolds et al., 2024; Elsaie, 2016). That's a big reason so many people with persistent acne have never had the right labs run. For how this plays out in a clinic, see do dermatologists do blood tests for acne.

Blood tests for acne: the labs that matter and what our panel covers

Here are the labs for acne that come up most in research and in clinics, what each one shows, and where it sits on the BreakoutLabs Acne Root Cause Test. "Yes" means it's in the 19-biomarker main panel. "Add-on" means you can add it to the same sample after purchase.

Marker	What it shows	On our test
Hormones
Total testosterone	All testosterone in your blood, bound and unbound	Yes
Free testosterone	The unbound, active portion that can reach your oil glands	Yes
SHBG	The protein that holds testosterone inactive. Low SHBG means more of it is free	Yes
DHEA-S	An androgen made mostly by the adrenal glands	Yes
Free androgen index (FAI)	Total testosterone relative to SHBG, a quick read on the balance between the two	Yes
Albumin	A blood protein that also binds testosterone, used to read free testosterone in context	Yes
Blood sugar and metabolism
HbA1c	Your average blood sugar over about three months	Yes
Average glucose (eAG)	Your HbA1c expressed as an estimated average blood sugar	Yes
Total cholesterol, HDL, LDL, VLDL	The main blood fats, which shift with metabolic health	Yes
Triglycerides	A blood fat that shifts with metabolic health and is often read next to HDL	Yes
Cholesterol/HDL and LDL/HDL ratios	How your cholesterol types balance against each other	Yes
Liver and kidney
ALT	A liver enzyme that rises when the liver is under strain	Yes
Creatinine and eGFR	How well your kidneys filter your blood	Yes
AST, ALP, GGT, bilirubin, total protein, BUN	A fuller liver and kidney picture	Add-on (Liver and Kidney+, $39)
Nutrients
Vitamin D (25-OH)	Your vitamin D status	Yes
Ferritin, iron, UIBC, TIBC, transferrin saturation	Iron stores and how iron moves through your blood	Add-on (Iron, $39)
Thyroid
TSH, Free T4, TPO antibodies	Thyroid function and thyroid autoimmunity	Add-on (Thyroid, $49)
Ordered by a doctor for specific conditions
LH and FSH	Pituitary hormones a doctor may check when PCOS or cycle problems are suspected	No
Prolactin and 17-OH progesterone	Used to rule out other causes of high androgens	No
Androstenedione	Another androgen, sometimes checked if testosterone is normal	No
Fasting insulin	Insulin levels. Routine insulin tests aren't recommended in everyday PCOS care (Teede et al., 2023)	No
Estrogen and progesterone	Cycle hormones that change by the day	No
Cortisol, hsCRP, vitamin B12	Stress hormone, general inflammation and B12 status	No

The international PCOS guideline recommends total and free testosterone first, then androstenedione and DHEA-S if those aren't raised, and lists TSH, prolactin, 17-OH progesterone and FSH among the tests used to rule out other causes (Teede et al., 2023). If PCOS is on your mind, read hormonal acne and PCOS.

Hormones: the part of the panel with the most research

Hormones are where acne research is deepest. The pattern that matters is often not one number but how testosterone, SHBG and DHEA-S sit together.

• SHBG and severity: in 129 adult women with acne, most had at least one raised androgen, only 19% had PCOS, and lower SHBG went with more severe acne (Borgia et al., 2004).
• Low SHBG as the common thread: in 112 women with persistent acne, low SHBG was the most frequent hormonal finding (Sardana et al., 2016).
• DHEA-S in adult-onset acne: in women whose acne started after 25, DHEA-S was the only marker that differed from controls in those without unwanted hair growth (Seirafi et al., 2007).
• Adrenal androgens: in adult women with acne, raised adrenal androgens were common (Bansal et al., 2020).

Free testosterone reflects active hormone better than the total, and it can be calculated from total testosterone and SHBG (Vermeulen et al., 1999). The free androgen index is a simpler ratio of the two, so it's most useful next to the other markers, not alone. That's why a "normal testosterone" result can still miss a hormonal pattern. More in testosterone and acne, low SHBG and acne and normal bloodwork but still have acne.

Why blood sugar and metabolism markers matter for your skin

Hormones don't act in isolation. Blood sugar and metabolism sit upstream of them, which is why the panel pairs the two. Here's how the connection works.

• Insulin and SHBG move together. In obese women with PCOS, lowering insulin with medication raised SHBG by 32% and cut non-SHBG-bound testosterone by 43%, which suggests high insulin pushes SHBG down and leaves more testosterone free (Nestler et al., 1991). Lab research adds that glucose and fructose reduce SHBG production by liver cells (Selva et al., 2007).
• Low SHBG tracks with metabolic risk. Lower SHBG has been linked to a higher risk of type 2 diabetes in both women and men (Ding et al., 2009).
• Diet changes show up in the skin. In a 12-week trial in young men, a low-glycemic-load diet reduced acne lesions more than a high-glycemic diet and improved insulin sensitivity (Smith et al., 2007).
• Blood fats can flag a pattern. Women with PCOS tend to have higher triglycerides and LDL and lower HDL (Wild et al., 2011). In a study of 351 people with severe acne, higher triglycerides and lower HDL at baseline were each linked to acne returning after isotretinoin, alongside a higher free androgen index, higher DHEA-S and lower SHBG (Song et al., 2026).

So what do the markers tell you? HbA1c and average glucose show your blood sugar over about three months, not one lucky or unlucky morning. Cholesterol, LDL, HDL, VLDL, triglycerides and the two ratios show how your body is handling fat and sugar. When they're read next to your SHBG and free testosterone, you can see whether a metabolic thread runs through your hormones. The guideline for PCOS describes HbA1c as a simpler, less precise way to check blood sugar than a glucose tolerance test, and recommends a lipid profile at diagnosis (Teede et al., 2023). Insulin itself isn't on the panel: HbA1c and SHBG are the practical clues.

Liver and kidney markers: how your body handles meds and supplements

ALT, creatinine and eGFR may look out of place on an acne panel. They're there because your liver and kidneys are the organs that break down and clear most of what you take: prescriptions, supplements and the ingredients in products you use every day. Seeing how they're doing gives you a baseline before you add or change anything.

• ALT is a liver enzyme that rises when the liver is under strain. It's one of the labs dermatologists use when monitoring some acne treatments: a 2022 consensus of 22 acne specialists settled on ALT and triglycerides before starting isotretinoin and at peak dose (Xia et al., 2022). Serious liver abnormalities on isotretinoin are rare, but baseline and follow-up numbers are how they're caught (Barbieri et al., 2020).
• Creatinine and eGFR show how well your kidneys filter your blood. If you take daily supplements or are comparing acne treatment options, they give you and your doctor a clear starting point.
• The liver also makes SHBG, the protein that decides how much testosterone is free (Selva et al., 2007). So liver health and hormone balance are connected.

If you want a fuller picture, the Liver and Kidney+ add-on ($39) adds AST, ALP, GGT, bilirubin, total protein and BUN on the same sample. To go deeper on lab checks around acne medications, see Accutane blood tests.

Vitamin D and acne

Vitamin D is the one nutrient on the main panel, and it's one of the better-studied ones for acne. A meta-analysis of 13 studies found vitamin D was about 9 ng/mL lower in people with acne than in people without it, deficiency was nearly three times as common, and lower levels went with more severe acne (Hasamoh et al., 2022). A systematic review found that 8 of 10 studies showed vitamin D falling as acne got more severe (Rasti et al., 2022). In a small trial, people with acne and low vitamin D had fewer inflammatory lesions after two months of supplementing (Lim et al., 2016).

Low vitamin D rarely causes obvious symptoms, and it's common, so you can't guess your level. Testing also means you supplement only if you need to. For the full picture, read vitamin D and acne.

Add-ons: iron and thyroid, and when they're worth it

The 19-biomarker main panel covers the core drivers. If something else in your history stands out, you can add a panel to the same sample after you buy, up to two per kit. You don't need another collection.

Add-on	What it measures	Worth adding if
Iron ($39)	Ferritin, iron, UIBC, TIBC and transferrin saturation	You have heavy periods, eat a mostly plant-based diet, or feel tired or notice hair shedding
Thyroid ($49)	TSH, Free T4 and TPO antibodies	You have fatigue, changes in your cycle, or a family history of thyroid problems
Liver and Kidney+ ($39)	AST, ALP, GGT, bilirubin, total protein and BUN	You take regular medications or supplements and want a fuller baseline

Why iron. Low iron is more common than most people think: in US survey data from 2003 to 2020, almost 40% of females aged 12 to 21 had iron deficiency (Weyand et al., 2023). Between 18% and 50% of females meet the criteria for heavy menstrual bleeding, and it often goes undiagnosed (Sholzberg et al., 2025). Vegetarians tend to have lower ferritin than meat-eaters (Haider et al., 2018). Low iron and acne can show up together: in people with severe nodular acne, low blood iron was common and returned to normal once the acne was treated (Leyden, 1985). You can't tell your iron status by how you feel, and supplementing blind can backfire, so checking comes first. See can low iron cause acne and low ferritin and acne.

Why thyroid. The PCOS guideline lists TSH among the tests used to rule out other causes when androgens look high or cycles are irregular (Teede et al., 2023), and studies of adult women with acne have included thyroid tests in the workup (Bansal et al., 2020). If your acne arrives with fatigue or cycle changes, thyroid is a reasonable add-on to check next to your hormones.

Who should get a blood test for acne?

A blood test isn't needed for occasional breakouts. It's most useful when one or more of these apply:

• Your acne hasn't improved with consistent topical or prescription treatment (Elsaie, 2016)
• Your periods are irregular, or you have unwanted facial or body hair (Elsaie, 2016; Teede et al., 2023)
• Your acne started or came back as an adult. See adult-onset acne
• Your breakouts sit on the chin and jaw, or flare with your cycle
• Your skin changed after stopping the pill. See acne after stopping birth control
• You've been told your "hormones are normal," but only total testosterone was checked
• You're thinking about acne medication, or you take supplements, and want a baseline first

At-home acne test vs a doctor or lab draw

You can get tests for acne two ways: a doctor orders them and you go to a lab for a vein draw, or you collect a small sample at home and mail it to a lab. Both give you numbers. They differ a lot in effort.

	Doctor or lab draw	At-home test
Getting it ordered	Book a visit, ask for the right tests, and hope your doctor will order a broad panel for acne	No appointment: a physician orders each test for you
How blood is collected	Lab slip, trip to a draw center, needle draw	A painless device on the back of your upper arm, at home
Which markers	Whatever your doctor orders, often a generic panel	19 biomarkers chosen for acne, with iron, thyroid and liver and kidney add-ons
Cost	Depends on insurance and how tests are ordered	Fixed price, HSA/FSA eligible
What comes back	Numbers, explained at a follow-up visit	Numbers plus a personalized Clear Skin Blueprint that reads them for acne
Best for	Suspected PCOS, thyroid or adrenal conditions, and prescription decisions	Getting a clear first picture fast, or bringing data to a doctor

On accuracy: whichever route you choose, check that the lab is CLIA-certified. Upper-arm capillary devices are newer than vein draws. In one 2026 study of a different upper-arm device, 13 of 16 routine chemistry markers met accuracy targets against vein draws, and people rated it far less painful (Beal et al., 2026). That study didn't test hormones, so it supports the method in general, not every marker. If your results show something significant, bring them to a physician or endocrinologist.

How to prepare for an acne lab test

Timing changes some of these numbers, so preparation matters as much as the test itself.

• Test in the morning, fasted. The BreakoutLabs kit asks for an 8 to 10 hour fast, with water allowed, and collection within 1 to 2 hours of waking. Fasting matters most for the blood sugar and blood fat markers, which move with your last meal.
• Time it to your cycle. If you menstruate, collect on days 3 to 7 of your cycle (day 1 is the first day of your period). Reviews recommend hormone testing in the early, follicular part of the cycle (Elsaie, 2016), and one adult acne study used morning, fasting samples on days 3 to 5 (Bansal et al., 2020).
• Tell your doctor about birth control. The pill raises SHBG and lowers androgens, which makes hormone results hard to read. Advice on stopping before testing ranges from one month (Elsaie, 2016) to at least three months when testing is essential (Teede et al., 2023). Never stop a medication without talking to your prescriber.
• Note your supplements. Write down anything you take. Biotin, common in hair, skin and nail products, can interfere with some lab tests, including thyroid tests (Shing et al., 2025).

What acne blood test results can and can't tell you

They can:

• Show a hormone pattern, like low SHBG with high-normal free testosterone, that a single total testosterone result would miss
• Show whether blood sugar and metabolism are running alongside your hormones
• Flag a low vitamin D, and low iron or thyroid changes if you add those panels
• Give you a baseline for how your liver and kidneys are doing before you start or change a medication or supplement
• Give you and your doctor a starting point to retest against

They can't:

• Diagnose PCOS, thyroid disease or an adrenal condition on their own
• Prove that one marker is causing your acne. The studies above show links, not certainty
• Capture what blood doesn't reflect, like skincare products, friction, genetics or how sensitive your skin is to normal hormone levels

Normal results are useful too. If every marker comes back in range, that makes it more likely the driver lies outside what was measured, which can save months of guessing. A result inside the standard range can still matter in context: low-normal SHBG, for example, or high-normal HbA1c next to high-normal free testosterone. That's why your numbers are read for acne, not just against a lab's flag.

Why test with BreakoutLabs

Asking which blood tests to get for acne is really asking what's driving yours. BreakoutLabs checks the main suspects in one go:

• At home, with a painless device on your upper arm. No lab visit, no appointment, no waiting room.
• 19 biomarkers across hormones, blood sugar, metabolism and nutrients: Free and Total Testosterone, SHBG, DHEA-S, Free Androgen Index and Albumin; HbA1c, average glucose, total cholesterol, HDL, LDL, VLDL, triglycerides and two cholesterol ratios; ALT, Creatinine and eGFR; and Vitamin D.
• Iron, Thyroid or Liver and Kidney+ add-ons on the same sample, if your history calls for them.
• Results in 5 business days after a CLIA-certified lab receives your sample.
• A personalized Clear Skin Blueprint that reads your results through the lens of acne.
• HSA/FSA eligible, and backed by our 30-day money-back guarantee.

Collect in the morning after an 8 to 10 hour fast, Monday to Thursday, and on days 3 to 7 of your cycle if you menstruate. For ages 14 and up (14 to 17 with a parent or guardian). The test is information to act on and share with your doctor, not a treatment.

What customers say

In their own words, after testing instead of guessing.

Frequently asked questions

Is there a blood test for acne?

Not one that diagnoses acne, which is diagnosed by looking at your skin. But blood tests can look for drivers like low SHBG, raised DHEA-S, high blood sugar markers or low vitamin D. They're most useful for persistent, adult or hormone-pattern acne.

What blood tests should I get for acne?

Start with total testosterone, free testosterone, SHBG and DHEA-S, then add blood sugar and cholesterol markers (HbA1c, average glucose, lipids), liver and kidney markers and vitamin D. Iron and thyroid are worth adding if you have fatigue, heavy periods or hair shedding. A doctor may add LH, FSH, prolactin or 17-OH progesterone if PCOS or another condition is suspected.

Can a blood test show hormonal acne?

A hormonal acne blood test can show patterns linked to acne, like low SHBG or raised DHEA-S. It can't prove those are the cause on their own, so results are read alongside your symptoms, cycle and history.

Does blood sugar affect acne?

It can be part of the picture for some people. Higher insulin is linked to lower SHBG, which leaves more testosterone free, and a low-glycemic-load diet reduced acne lesions in a 12-week trial in young men. HbA1c and average glucose show your blood sugar over about three months, so you can see where you stand.

Why does an acne test include liver and kidney markers?

Your liver and kidneys process and clear medications and supplements, and the liver also makes SHBG. ALT, creatinine and eGFR give you a baseline for how those organs are doing, which is useful if you're considering acne medication or taking supplements.

Does the test include iron or thyroid?

They're optional add-ons on the same sample, not part of the 19 main biomarkers. Iron ($39) adds ferritin, iron, UIBC, TIBC and transferrin saturation. Thyroid ($49) adds TSH, Free T4 and TPO. You add them after purchase, up to two per kit.

Is an at-home acne test accurate?

It depends on the lab and the collection method. Look for a CLIA-certified lab, follow the timing and fasting instructions closely, and know which markers are included. Early evidence on upper-arm collection devices is encouraging for routine chemistry markers.

Do I need to fast before an acne lab test?

The BreakoutLabs test asks for an 8 to 10 hour fast with water allowed, and a morning collection. Ask your lab or doctor what applies to the tests they order.

Can I use my HSA or FSA for an acne blood test?

Yes. The BreakoutLabs Acne Root Cause Test is HSA/FSA eligible, so you can pay with your HSA or FSA card at checkout.

Does birth control affect acne blood test results?

Yes. The pill raises SHBG and lowers androgens, which can make hormone results look normal. Tell your doctor what you take, and don't stop it without their advice.

Sources

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• Elsaie ML. Hormonal treatment of acne vulgaris: an update. Clinical, Cosmetic and Investigational Dermatology. 2016.
• Teede HJ, Tay CT, Laven JJE, et al. Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Journal of Clinical Endocrinology and Metabolism. 2023.
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This article is for educational purposes and is not medical advice. Talk to your healthcare provider about testing and treatment.