Acne Blood Test: Which Labs to Ask For and Why

What Blood Tests Should You Get for Persistent Acne?

Short answer: There is no single acne blood test, but a small set of labs for acne can show whether hormones, inflammation, nutrients or blood sugar are part of the picture. If you're asking what blood tests you should get for acne, the core hormonal acne blood test is total testosterone, free testosterone, SHBG and DHEA-S. Many people add vitamin D, B12, ferritin, HbA1c, hsCRP and morning cortisol. A doctor may also order LH, FSH, prolactin, 17-OH progesterone or TSH when PCOS or another condition is suspected. Most acne is diagnosed without bloodwork, so testing makes the most sense when acne is persistent, adult-onset, or comes with other hormone signs.

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's not a test that diagnoses acne itself: your skin does that. It's a way to see whether something measurable, like a low SHBG or a low vitamin D, might be contributing.

Most people with acne never need one. Dermatology guidelines focus on treatments, not routine labs (Reynolds et al., 2024). Reviews of hormonal acne suggest a hormone workup when there are signs of excess androgens, irregular periods, or acne that doesn't respond to standard treatment (Elsaie, 2016). For more on how this plays out in a clinic, see do dermatologists do blood tests for acne.

Blood tests for acne: every marker worth knowing

Here are the labs for acne that come up most in research and in clinics, what each one shows, and whether the BreakoutLabs Acne Root Cause Test measures it. We've included the ones we don't measure, because a full picture is more useful than a sales pitch.

Marker	What it shows	Measured by BreakoutLabs?
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 free testosterone	Yes
DHEA-S	An androgen made mostly by the adrenal glands	Yes
Albumin	A blood protein that also binds testosterone; used to read free testosterone in context	Yes
Cortisol (morning)	Your main stress hormone at one point in time	Yes (single morning value, not a daily curve)
hsCRP	Low-grade inflammation in the body	Yes
Vitamin D (25-OH)	Vitamin D status	Yes
Vitamin B12	B12 status, low or high	Yes
Ferritin	Your iron stores	Yes
Creatinine	A general kidney function marker	Yes
HbA1c	Average blood sugar over about three months	Yes
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
TSH (thyroid)	Thyroid function	No
Fasting insulin and glucose	Insulin resistance and blood sugar right now	No (HbA1c is the blood sugar marker we include)
Estrogen and progesterone	Cycle hormones	No
Zinc, serum iron, biotin	Individual nutrient levels	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.

Hormonal acne blood test: what the research shows

An acne hormone test is the part of the panel with the most research behind it. 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 and stress: in adult women with acne, raised adrenal androgens were common, and many of the women with abnormal DHEA-S reported moderate to severe stress (Bansal et al., 2020).

Free testosterone matters because it reflects active hormone better than the total, and it can be calculated from total testosterone and SHBG (Vermeulen et al., 1999). That's why a "normal testosterone" result can still miss a hormonal pattern. More on that in low SHBG and acne and normal bloodwork but still have acne.

These are observational studies, mostly in women. They show links, not proof that one hormone causes breakouts.

Beyond hormones: inflammation, nutrients and blood sugar

The evidence for non-hormone markers is more mixed, and it's worth being straight about that.

Vitamin D: a meta-analysis of 13 studies found lower vitamin D in people with acne than in controls, with lower levels linked to more severe acne (Hasamoh et al., 2022). In one small trial, people with acne and low vitamin D saw fewer inflammatory lesions after supplementing (Lim et al., 2016).
Vitamin B12: B12 cuts both ways. One study found B12 deficiency more often in people with acne (Alharbi et al., 2023), while lab research showed B12 can shift skin bacteria toward inflammation, which may explain why high-dose B12 triggers breakouts in some people (Kang et al., 2015). See vitamin B12 and acne.
Ferritin: results are mixed. One study found no difference in ferritin between women with adult acne and controls (Balta et al., 2013), and another found lower ferritin in the acne group that didn't reach significance (Alharbi et al., 2023). See low ferritin and acne.
hsCRP: one study found no difference between people with moderate to severe acne and controls (Namazi et al., 2015), while a larger 2025 study found higher hsCRP in more severe acne (Bhoi et al., 2025). See inflammatory acne and hsCRP.
Blood sugar: 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). HbA1c gives a three-month view of blood sugar; it doesn't measure insulin directly.

Who should get a blood test for acne?

A blood test for pimples 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 or with stress
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 take supplements like high-dose B12 and want to know whether they could be involved

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 an acne testing lab. Both can be useful. They suit different situations.

	Doctor or lab draw	At-home acne test
How blood is collected	Vein draw at a clinic or lab	Small sample you collect at home
Which markers	Whatever your doctor orders, including LH, FSH, TSH, prolactin and insulin	A fixed panel; check exactly what's included
Cost	Depends on insurance and how the tests are ordered	Fixed price, paid upfront
Getting it ordered	Needs a visit, and some doctors won't order a broad panel for acne	No appointment needed; a physician orders each test
What comes back	Numbers, explained at a follow-up visit	Numbers plus a written explanation
Best for	Suspected PCOS, thyroid or adrenal conditions, and prescription decisions	Getting a clear first picture, or bringing data to a doctor

On accuracy: whichever route you choose, check that the acne testing 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.

At-home testing doesn't replace a doctor. If your results show something significant, follow up with 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. Cortisol rises sharply in the first 30 to 45 minutes after waking (Stalder et al., 2016) and changes through the day (Adam et al., 2017), so a morning sample is easier to compare against reference ranges.
Fast if your test asks for it. The BreakoutLabs kit asks for an 8 to 10 hour fast, with water allowed, and collection within 1 to 2 hours of waking.
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, especially vitamin D and B12, so results are read in context.

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
Flag a low vitamin D, B12 or ferritin worth discussing
Give you and your doctor a baseline to retest against
Point toward when a doctor should look further, for example at PCOS

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 things blood doesn't reflect, like skincare products, friction, genetics or how sensitive your skin is to normal hormone levels
Replace the tests a doctor may add, like LH, FSH, TSH or insulin

Normal results are useful too. They make it more likely the driver lies outside what was measured, which can save months of guessing.

What to ask your doctor

If you'd rather go through your own doctor, it helps to be specific. You could say: "I have persistent acne that hasn't responded to treatment, and I'd like to check for hormonal and metabolic drivers." Then ask:

Can we check total testosterone, free testosterone, SHBG and DHEA-S together?
Given my cycle and symptoms, should we add LH, FSH, prolactin, 17-OH progesterone or TSH?
Should we check vitamin D, B12, ferritin and HbA1c?
When in my cycle, and what time of day, should I have blood drawn?
Will my birth control or supplements affect these results?
If results are borderline, what would change our treatment plan?

Coverage varies, and hormone panels are more likely to be covered when ordered for a specific concern like irregular periods or suspected PCOS. Ask before your draw.

How BreakoutLabs fits in

The BreakoutLabs Acne Root Cause Test measures 19 biomarkers: Free Testosterone, Total Testosterone, SHBG, DHEA-S and Albumin (hormones); Cortisol and hsCRP (stress and inflammation); Vitamin D, Vitamin B12, Ferritin and Creatinine (nutrients and recovery); and HbA1c (blood sugar). It does not measure estrogen, progesterone, insulin, glucose, TSH, zinc, serum iron or biotin.

You collect a small blood sample at home with a painless device on the back of your upper arm, Monday to Thursday, in the morning after an 8 to 10 hour fast. Samples are processed in a CLIA-certified lab, and results are ready 5 business days after the lab receives your sample, with a personalized Clear Skin Blueprint that explains your pattern. The test is for ages 14 and up, with a parent or guardian for teens 14 to 17. It's information to act on and share with your doctor, not a treatment. It's backed by a 30-day money-back guarantee.

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 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. Many people add vitamin D, B12, ferritin, HbA1c, hsCRP and morning cortisol. A doctor may add LH, FSH, prolactin, 17-OH progesterone or TSH 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.

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. At-home tests don't replace follow-up testing your doctor may want.

Do I need to fast before an acne lab test?

It depends on the 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.