On your lab requisition: Labcorp “Lithium (Eskalith(R)), Serum” (test no. 007708)
The short answer
Measures the level of lithium in your blood — used to monitor patients taking lithium for bipolar disorder or related mood conditions, measured from a standard blood draw. At TestWell it costs $29.00 plus a $6 lab processing fee, needs no fasting, and results post in 2–4 business days. Physician-authorized with no doctor's visit or insurance needed; draw at Quest or Labcorp.
Hospital Lab
$120
cash pay
Other Labs
$90
+ lab fees
TestWell
$29.00
+ $6 lab processing fee
A lithium level test measures the concentration of lithium in your blood. It's primarily used for therapeutic drug monitoring in people taking lithium for bipolar disorder or other mood conditions. Because lithium has a narrow therapeutic window, regular monitoring helps confirm the dose is high enough to be effective without climbing into the toxic range that can affect the kidneys, thyroid, and nervous system. Results are most accurate when the sample is drawn as a trough — about 12 hours after the last dose.
Measures the concentration of lithium in your blood to ensure levels stay within the narrow therapeutic range. Too little may mean inadequate mood stabilization; too much can cause toxicity. Used exclusively for monitoring patients already taking lithium — not a diagnostic test for lithium deficiency.
Anyone currently prescribed lithium for bipolar disorder or related mood conditions who needs routine therapeutic drug monitoring, has recently had a dose change, is experiencing symptoms that could indicate toxicity (tremor, nausea, confusion), or whose prescriber has requested a trough-level check.
Sample Type
Blood draw
Fasting
Not required
Results In
2–4 business days · typical; varies by lab and draw day
Performed At
Quest or Labcorp
1 biomarker tested
Your Lithium Level (Serum) results will include values for each of the 1 biomarker tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 2–4 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you. Already have results? Analyze them with your AI assistant against our physician-reviewed ranges.
No fasting required. For accurate monitoring, schedule your blood draw about 12 hours after your last lithium dose (a trough level), and tell the lab when you took your last dose.
The short answer
Yes if you take lithium — this is not an optional wellness test but the standard safety monitoring for a medication with a narrow therapeutic window: the blood level where lithium works and the level where it becomes toxic are close together. That's why it's monitored with blood tests rather than by how you feel, and why WHEN the sample is drawn matters as much as the number that comes back. At $29 it's far cheaper than the $90-120 the same draw bills elsewhere — but it is not a substitute for the monitoring schedule your prescriber sets; it's the affordable way to keep up with it.
We would rather you order the right test than the most expensive one.
Not available at home, deliberately. Lithium levels are interpreted as a 12-hour trough with tight timing, and mobile phlebotomy arrival windows span hours — a mismatch that breaks the whole basis of interpretation. A patient service center with a fixed morning appointment preserves the timing at no real cost, since a morning draw is what the trough convention needs anyway (for a once-daily evening dose, about 12 hours later means morning). Record the exact date and time of your last dose and bring it to the draw. Ask your prescriber how they want the timing handled before you schedule — do not change or skip a dose to hit a window.
An at-home draw is not recommended for this test — it needs a lab-based collection to be accurate.
The markers that matter most and what an out-of-range value can mean. Reference ranges vary by lab, age and sex.
| Marker | Typical range | What it means |
|---|---|---|
| Lithium level | Commonly cited maintenance range: roughly 0.6-1.0 mmol/L (some references use 0.4-1.0; lower targets around 0.4-0.8 are often used in older adults, higher around 0.8-1.2 for acute treatment). Your target is set by your prescriber, not by the lab's reference interval. | Risk of toxicity rises meaningfully above about 1.5 mmol/L; above 2.0 is serious. A result 'in range' for the lab may not be right for you — prescribers deliberately target different levels for different people and situations. Toxicity can also occur at levels that look normal, more often in older adults, during dehydration or illness, with reduced kidney function, and with medications including NSAIDs, ACE inhibitors, ARBs, and thiazide diuretics. |
This section medically reviewed by Youmna DiStefano, MD — updated August 2026. General health information, not medical advice; interpret results with a qualified clinician.
TestWell orders the same Lithium Level (Serum) the labs run for doctors' offices, so you can walk into any of these labs with our requisition — no doctor's visit, a licensed physician authorizes the order, and most patient service centers take walk-ins. The table shows each lab's own test code, the name printed on the requisition, what the lab charges on its own consumer site, and the price through TestWell at that lab (plus one $6 fee per order).
| Lab | Test code | On the requisition | Lab's own site | Through TestWell |
|---|---|---|---|---|
| Quest Diagnostics | test code 613 | “Lithium Level (Serum)” | not sold direct | $84.99 + $6 |
| Labcorp | test no. 007708 | “Lithium (Eskalith(R)), Serum” | not sold direct | $29.00 + $6 |
| BioReference (New York & New Jersey) | test code 0119-8 | “Lithium Level (Serum)” | n/a | $29.00 + $6 |
You choose the lab at checkout; the requisition is written for that lab and arrives by email within minutes. New York and New Jersey orders draw at BioReference. Lab-direct prices are read from the labs' public pages and re-checked regularly.
Where to get it near you: patient service centers by state and city · search by ZIP code
A Lithium Level (Serum) test costs $29.00 at TestWell — $35.00 all-in, since the $6 lab processing fee is charged once per order and there is no draw or physician fee. Hospital outpatient labs typically bill around $120.00 self-pay. With insurance you pay your plan's negotiated rate against your deductible; TestWell's price is fixed before the draw and HSA/FSA-eligible.
| Where you order | Price | One test, all-in | Notes |
|---|---|---|---|
| TestWell (drawn at Quest or Labcorp) | $29.00 | $35.00 | Includes the one $6 lab processing fee, charged once per order |
| TestWell (drawn at BioReference — New York & New Jersey) | $29.00 | $35.00 | New York and New Jersey orders route to BioReference; Quest Health and Labcorp OnDemand don't take self-ordered draws in those states |
| Hospital outpatient lab, self-pay (typical) | $120.00 | $120.00 | Reference figure; hospital charges vary widely by facility and are often higher |
Lab test codes: Quest test code 613 · Labcorp test no. 007708 · BioReference code 0119-8. Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
Compare more: Quest Diagnostics price list · Labcorp price list · Quest vs Labcorp · Lab test price checker
Yes. TestWell uses CLIA-certified partner labs including Quest Diagnostics and LabCorp patient service centers. After you order on TestWell, you'll receive a digital requisition you can take to any participating walk-in location near you.
TestWell's lithium level test is $29.00. Quest's direct cash-pay price is $90, and hospital or clinic labs typically bill around $120 without insurance. You're getting the same CLIA-certified result — TestWell just removes the institutional markup.
Not quite — lithium monitoring requires a venous blood draw, not a finger-prick home kit. However, TestWell makes it nearly as convenient: order online, walk into a nearby partner lab with no appointment needed, and get results in 2–4 business days without visiting a doctor's office first.
Yes. Lithium has one of the narrowest therapeutic windows of any psychiatric medication, so blood levels must be checked regularly — typically more often when starting or adjusting doses, and at least every few months once stable. Your prescriber will advise your specific schedule.
No fasting is required. What matters most for accuracy is timing: schedule your draw approximately 12 hours after your last lithium dose to capture a trough level. Be prepared to tell the lab what time you took your last dose — this context is essential for interpreting results correctly.
A trough level is the lowest concentration in your blood — measured just before your next dose (typically 12 hours after the previous one). It's the standardized reference point clinicians use to assess whether your dose is within the therapeutic range. Drawing at a different time can make levels appear artificially high or low.
Results are available in 2–4 business days after your blood draw. You'll receive them digitally through your TestWell account. Share the report with your prescribing provider, who can advise on any next steps.
The lithium serum test measures drug concentration only. Providers often also monitor kidney function and thyroid function alongside lithium therapy, since the medication can affect both over time. You can browse the full test catalog to find those panels if your provider has recommended additional monitoring.
Lithium is not an essential nutrient, so there is no recognized "lithium deficiency" or a reference range for people who do not take it. The serum lithium test exists for one purpose: therapeutic drug monitoring in people prescribed lithium for bipolar disorder or related mood conditions, where the target range is narrow and the level is drawn as a 12-hour trough. If you feel unwell and are not on lithium, other markers — thyroid, B12, iron, vitamin D — explain far more.
Lithium levels are interpreted as a 12-hour trough — a sample drawn about 12 hours after your last dose, before the next one. For a once-daily evening dose, that generally means a morning draw. A sample drawn at any other point can read falsely high or falsely low, and a mistimed lithium level is worse than no lithium level, because it can look reasonable while being wrong. Record the exact date and time of your last dose and bring it to your draw, and ask your prescriber how they want the timing handled — do not change or skip a dose to hit a window.
Testing frequency is set by your prescriber. As general reference: levels are checked frequently around starts and dose changes (lithium takes roughly 5 days to reach a steady level), then commonly every 3 to 6 months once stable — and usually rechecked sooner after anything that changes how your body handles lithium: a new medication, an illness with vomiting or diarrhea, dehydration, or a significant change in salt intake. This isn't a test to put on your own calendar; coordinate it with whoever prescribes it.
Coarse hand tremor, vomiting or diarrhea, unsteadiness, slurred speech, confusion, or unusual drowsiness — seek medical care now rather than waiting for a lab result. Toxicity can occur at blood levels that look normal, especially in older adults, during dehydration or illness, with reduced kidney function, or alongside NSAIDs, ACE inhibitors, ARBs, and thiazide diuretics.
Kidney function (creatinine/eGFR), thyroid (TSH), and calcium are typically monitored alongside lithium every 6 to 12 months, because long-term lithium can affect all three. A CMP covers the kidney piece and a TSH covers the thyroid piece if your prescriber wants them between visits.
No. A lithium level only means something when interpreted against your timing, your history, and your target — which your prescriber sets. Bring the result to them; never change your dose based on a number alone.
The CPT code for a Lithium Level (Serum) test is 80178. You can order it from TestWell for $29.00 — no doctor's visit or insurance required, with results in 2–4 business days.
The Lithium Level (Serum) test is Quest Diagnostics test code 613, Labcorp test number 007708 ("Lithium (Eskalith(R)), Serum"), BioReference code 0119-8 (CPT 80178). TestWell orders it under those codes for $29.00 at Quest, Labcorp or BioReference — no doctor's visit or insurance required, results in 2–4 business days. Codes verified against the labs' catalogs in 2026.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
TestWell Price
$29.00
+ $6 lab processing fee at checkout
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