Interaction charts on this desk are for reading, not for writing a prescription or filling a bottle. Open the orbit disclaimer
Orbit · Orbit · Endocrine
Last reviewed · 13 min read · Updated
Orbit card
| Onset | TSH lags 6-8 weeks after a change |
|---|---|
| Duration | Daily; long T4 pool |
| Food | Empty stomach; wait before coffee |
| Alcohol | Not a direct block; still skip chaotic nights before labs |
Orbit · levothyroxine (Synthroid 25 mcg start row and generics). Timing desk - not a thyroid titrate-by-mail service.
Coffee can cut levothyroxine absorption. The boring map is an empty stomach, then thirty to sixty minutes before coffee or breakfast. People who have washed 25 mcg with espresso for a year wonder why TSH never sits.
Calcium and iron binders need about four hours. A 'I will forget later' combined swallow is the usual noisy TSH.
If the clock is the question, the timing orbit is the hour map. This page is the interaction grid.
The Caelum lock is generic levothyroxine 25 mcg, ninety tablets. Brand Synthroid is a different NDC. Empty-stomach timing still applies.
Caelum does not dispense.
Generic levothyroxine 25 mcg x 90, GoodRx tablet table, 21 August 2026.
Generic levothyroxine 25 mcg, ninety tablets, the Caelum Synthroid start orbit, August 2026. GoodRx lists 25 mcg x 90 at $10.00 retail and $10.00 with a coupon. Fifty-microgram thirties are another default ($4.00 / $4.00). Empty-stomach timing still applies. Brand Synthroid is a different NDC. Caelum does not dispense.
Product switches deserve a six-to-eight-week TSH, not the old annual date. Narrow index.
Pregnancy often needs more T4. 25 mcg is a start lock, not a freeze. Obstetrics owns targets.
Estrogen starts and some anticonvulsants can raise T4 need. Name new hormones at the till.
Fifty-microgram thirties are another cash default. Do not treat 25 mcg as a forever personality.
Weekly missed doses still show on the next TSH. Most mornings is an adherence story.
Hold high-dose biotin before thyroid immunoassays per the lab. Write the hold on the form.
Coffee in the same swallow is the everyday absorption fail. Thirty to sixty minutes empty is the boring map.
Calcium and iron need about four hours. Sucralfate and bile-acid resins share the binder idea.
PPIs can lower uptake for some patients. Consistency plus a TSH recheck beats a midnight PPI shuffle.
Orlistat can cut T4. Recheck TSH after that capsule starts.
Coffee can cut levothyroxine absorption. The boring map is an empty stomach, then thirty to sixty minutes before coffee or breakfast. People who have washed 25 mcg with espresso for a year wonder why TSH never sits.
Calcium and iron binders need about four hours. Prenatal iron with 25 mcg because pregnancy already changed the dose still needs the gap. A combined swallow is the usual noisy TSH.
Sucralfate and bile-acid resins share the binder idea. Huge soy or fiber shifts can move absorption. Fix timing before anyone doubles micrograms.
PPIs and other acid reducers can lower uptake for some patients. Omeprazole moved to morning with Synthroid 25 to simplify is a same-swallow fail. Consistency plus a TSH recheck beats a midnight PPI shuffle.
Orlistat is a lipase neighbor that can also cut T4. Last year's TSH on 25 mcg is not this interaction. Recheck after Xenical starts. See the orlistat orbit.
High-dose biotin wrecks some immunoassays. Hold per lab advice - often a couple of days. Write the hold on the form. Gummies can fake a crisis.
Iodinated contrast and recent biotin are interpretation wreckers. Repeat with a hold plan rather than changing 25 mcg the same afternoon.
Product switches deserve a six-to-eight-week TSH, not the old annual date. Narrow index. Do not double a generic after a manufacturer change until the window.
Twenty-five micrograms is a start lock, not a forever personality. Fifty-microgram thirties are another cash default. Pregnancy often needs more T4. Obstetrics owns targets. Do not freeze 25 mcg because it is the Caelum lock.
Estrogen starts and some anticonvulsants can raise T4 need. Name new HRT at the till. Book a window. Do not wait a year and do not double 25 mcg because you feel tired.
Weekly missed doses still show on the next TSH. Five missed dawns plus five tablets on Sunday is a bolus, not a catch-up. Resume the usual map and tell the clinic.
Chest pain or severe palpitations are urgent. Mild jitter after a coffee-timing fix is a call, not a flush of the bottle.
Peer-pass wants swallow time and manufacturer on the same slip. Ingrid does not titrate mcg by thread.
Sources stay DailyMed administration and monitoring. Take-with-breakfast slogans do not override absorption math.
Educational only. Severe palpitations: 112. Reviewed 21 August 2026.
Chest pain or severe palpitations are urgent. Mild jitter after a coffee-timing fix is a call, not a flush.
Huge soy or fiber shifts can move absorption. Fix timing before anyone doubles micrograms.
Iodinated contrast wrecks interpretation. Repeat with a hold plan rather than changing 25 mcg the same afternoon.
Peer-pass wants swallow time and manufacturer on the same slip.
Sources stay DailyMed administration and monitoring. Take-with-breakfast slogans do not override absorption math.
| Item | Note |
|---|---|
| Chest pain or severe palpitations are ur | chart |
| Huge soy or fiber shifts can move absorp | till |
Divalent cations and some GI binders grab T4. Separate them. Soy and high-fiber habits can matter if they are new and huge.
PPIs and other acid reducers can lower absorption for some patients. Consistency plus a TSH recheck beats a midnight PPI shuffle.
Orlistat is a lipase neighbor that can also cut T4 uptake. See orlistat. Recheck TSH after that capsule starts.
| Partner | Issue | Desk move |
|---|---|---|
| Coffee / food | Less absorption | 30-60 min wait |
| Calcium / iron | Binding | ~4 h gap |
| PPI | Acid-dependent uptake | Stable habit + TSH |
| Orlistat | Malabsorption | Separate; retest |
| Biotin | Assay interference | Hold before draw |
Fifty-microgram thirties are another cash default. Do not treat 25 mcg as proof the diagnosis is mild forever.
Weekly missed doses still show on the next TSH. 'I take it most mornings' is an adherence story, not a binding story.
Chest pain or severe palpitations are urgent. Mild jitter after a coffee-timing fix is a call, not a flush of the bottle.
Laugavegur peer-pass wants swallow time and manufacturer on the same slip.
Sources stay DailyMed administration and monitoring. Forum 'take with breakfast for compliance' slogans do not override absorption math.
Five missed dawns plus five 25 mcg tablets on Sunday with coffee is a bolus. Resume the usual map. Tell the clinic before the next draw. Palpitations, chest pain, or new tremor is seek-care, not another 25 mcg to 'finish the catch-up.' The 25 mcg lock is a start board, not a weekend arithmetic toy.
Estrogen last month plus unchanged 25 mcg and exhaustion is a TSH window, not a kitchen doubling. Hormone therapy can raise T4 need. People who jump to 50 mcg because hair looks thinner invent thyrotoxic weeks. Book the blood. Do not invent the milligram.
Hair gummies and an unrecognizable TSH are an assay hold, not a double of T4. Biotin wrecks some assays. Hold biotin per the lab card and repeat. A wild number after a gummy month is not permission to swallow two 25 mcg tablets.
Pregnancy iron at dawn with 25 mcg because later vomiting is still a four-hour binder problem. Ask obstetrics for a nausea-proof timing map. Binding is binding even when the reason is hyperemesis rather than a lunch antacid.
Xenical lunch plus dawn Synthroid plus an eighteen-month-old TSH is not a current window. Recheck after orlistat. The lipase blocker and the binder list occupy the same month. See the orlistat orbit.
Peer-pass wants swallow time and manufacturer. Severe palpitations: 112. Reviewed 21 August 2026. Sources stay DailyMed administration. Educational only at Laugavegur 28. Brand Synthroid remains a different NDC from the 25 mcg generic start lock.
Calcium at bedtime and T4 at dawn can still collide if the 'dawn' swallow slid to 11:00 after a late shift. Write clock time, not meal name. Night-harbour workers need that sentence on the bag.
A new proton-pump week that coincides with a rising TSH is two absorption stories. Name both on the call. Do not double 25 mcg in silence because reflux treatment started.
Icelandic holiday weeks empty 25 mcg bottles and people invent Sunday boluses. Call for a bridge. Do not swallow five tablets with espresso because the pharmacy is closed until Tuesday.
Ingrid charts. She does not raise levothyroxine by thread. If the manufacturer changed and the TSH moved, say the manufacturer, not only the microgram.
High-dose biotin wrecks some immunoassays. Hold per lab advice - often a couple of days. Write the hold on the form.
Coffee in the same swallow is the everyday absorption fail. Thirty to sixty minutes of empty stomach is the boring map.
Calcium and iron need about four hours. Sucralfate and bile-acid resins share the binder idea.
PPIs can lower uptake for some patients. Consistency plus a TSH recheck beats a midnight PPI shuffle.
Orlistat is a lipase neighbor that can cut T4. Recheck TSH after that capsule starts.
Product switches deserve a six-to-eight-week TSH, not the old annual date. Narrow index.
Pregnancy often needs more T4. 25 mcg is a start lock, not a freeze. Obstetrics owns targets.
Estrogen starts and some anticonvulsants can raise T4 need. Name new hormones at the till.
| Noise | Fix |
|---|---|
| Biotin | Hold before draw |
| Coffee | Wait 30-60 min |
| Cations | ~4 h |
| Manufacturer swap | TSH 6-8 wk |
Do not stop T4 because you 'feel a bit fast.' Ideation and chest pain are urgent. Mild jitter after a coffee-timing fix is a call, not a flush of the bottle.
Biotin, contrast, and sick-day nonadherence wreck interpretation. Write the hold on the lab form.
Personal mcg changes stay with the clinician who sees this week's TSH.
Levothyroxine chips
Narrow therapeutic index. Product switches deserve a new TSH window. The TSH trace is the calendar.
25 mcg is the Caelum start lock. Fifty-microgram thirties are another default cash row. Do not treat 25 mcg as a pregnancy freeze - many people need more T4 when pregnant.
Estrogen starts and some anticonvulsants can raise T4 need. Name new hormones at the till.
| Absorption | Empty-stomach oral uptake; food and coffee cut it. |
|---|---|
| Distribution | Highly protein bound; large T4 pool. |
| Metabolism | Peripheral conversion to T3; not a CYP carnival for the parent story. |
| Excretion | Slow clearance; weekly missed doses still show on the next TSH. |
A new bottle that looks the same microgram and a different stamp is a TSH window after a few weeks, not a kitchen extra 25 mcg because hair looked thinner on Tuesday. Write the manufacturer on the bag. Peer-pass at Laugavegur 28 asks stamp before milligram when the story is a switch.
Soy latte every dawn with the 25 mcg swallow is an absorption experiment you can stop without a clinic visit. Move the latte. Do not add a second tablet because the first one 'never works with breakfast.' Coffee still sits on the same list.
Severe palpitations after a Sunday bolus someone already confessed are 112 or same-day care, not another 25 mcg to even out. Reviewed 21 August 2026. Educational only. Brand Synthroid remains a different NDC from the generic start lock.
Xenical still wants a later window. Calcium at a slid 11:00 swallow still binds. Pregnancy iron still binds. The 25 mcg lock is a start board. Ingrid does not raise it by thread.
Coffee, calcium, biotin, and orlistat outrank brand color. 25 mcg is a start, not a personality.
Companions: timing, TSH. Dose changes need the clinician who owns the lab.
Checked against the current label and reviewed by Dr. Ingrid Bergsson. See Lift, Chart, Peer-pass, Publish.
Levothyroxine timing thread at Laugavegur, peer-passed by Dr. Ingrid Bergsson. Educational only. Severe palpitations: 112.
Asta D., Reykjavik Coffee immediately after Synthroid 25 mcg - GP said it was fine.
Coffee can cut levothyroxine absorption. The usual map is an empty stomach, then a wait of thirty to sixty minutes before coffee or breakfast. If you have been washing 25 mcg with an espresso for months, the TSH may be chasing the coffee, not the milligram. See the timing orbit. Confirm with your clinician. Icelandic emergency: 112.
Jonas M., pharmacy Switch from brand Synthroid to generic 25 mcg - stay on the same TSH date?
Narrow-index thyroid hormone is sensitive to product switches. Recheck TSH in about six to eight weeks after a manufacturer change, not on the old annual date. The TSH trace is the window.
Ida M., miss Missed five dawns, took five tablets Sunday.
Do not bolus a week of T4. Resume the usual 25 mcg map and tell the clinic before the next draw. A Sunday stack can cause palpitations.
Jon P., contrast CT with contrast last week, TSH wild this week.
Iodinated contrast and recent biotin are interpretation wreckers. Repeat with a hold plan rather than changing 25 mcg the same afternoon. Tell the lab what happened.
Sara L., pregnant Stay on 25 mcg through pregnancy?
Many people need more levothyroxine in pregnancy. 25 mcg is a start lock, not a pregnancy freeze. Obstetrics owns the TSH targets. Do not stop because you feel 'a bit hyper.'
Asta P., stamp New manufacturer, same 25 mcg, hair thinner, wants 50 tonight.
Book a TSH window. Do not add a tablet. Write the stamp on the bag. Palpitations: seek care. Icelandic emergency: 112. The lock is 25 mcg. Brand Synthroid is a different NDC if that is what they intended.
Anna S., estrogen Started HRT. Stay on 25 mcg without a new TSH?
Estrogen can raise T4 need. Book a window. Do not wait a year. Do not double 25 mcg yourself because you feel tired.
Hildur W., Kopavogur Calcium tablet with the 25 mcg because I forget later?
Calcium and iron bind levothyroxine. Separate by at least four hours. A combined swallow is a common reason a 'stable' 25 mcg looks noisy on TSH.
Tomas E., biotin Hair gummies daily, TSH unrecognizable, almost doubled 25 mcg.
Hold biotin and repeat per the lab. Do not double T4 on a wrecked assay. Write the hold on the next form.
Petur A., Akureyri Biotin hair gummies before bloodwork?
High-dose biotin can wreck thyroid immunoassays. Hold biotin before the draw per lab advice - often a couple of days. A 'crazy TSH' after gummies may be the assay, not the 25 mcg.
Nanna L., gummies Biotin daily, wild TSH, almost doubled 25 mcg this morning.
Hold biotin and repeat per the lab. Do not double T4 on a wrecked assay. A wild number after gummies is an assay hold. If you already swallowed two tablets, say so before the repeat draw.
Kristjan D., iron Pregnant, iron at dawn with 25 mcg because later vomiting is worse.
Binding is still binding. Ask obstetrics for a nausea-proof timing map. Do not invent a double 25 mcg because you vomited at noon. Four-hour gaps still apply.
Stefan P., brand Generic 25 felt different after a manufacturer change. Double until TSH?
Do not double. Book the six-to-eight-week window. Narrow-index switches are lab events, not kitchen events.
Magnus T., Selfoss Orlistat lunch and levothyroxine dawn - still separate?
Yes. Orlistat can reduce levothyroxine uptake even if the clock looks far. Recheck TSH after orlistat starts. See orlistat.
Valgerdur S., sunday Took five 25 mcg tablets Sunday after a missed week, with espresso.
Do not bolus T4. Resume the usual 25 mcg map. Tell the clinic before the next draw. Palpitations: seek care. Icelandic emergency: 112. Coffee still sits on the absorption list. The catch-up already happened. Do not add a sixth tablet.
Elin S., Hafnarfjordur PPI every morning plus levothyroxine. Problem?
Reduced acid can lower absorption for some patients. Consistency and a TSH recheck beat a midnight PPI move. Do not stop the PPI because a forum blamed all reflux drugs equally.
Olafur B., sunday Missed five dawns, took five 25 mcg tablets Sunday with coffee.
Do not bolus a week of T4. Resume the usual map. Tell the clinic before the next draw. Palpitations: seek care.
Lara H., soy Huge soy lattes replaced coffee. TSH jumped on 25 mcg.
Large soy and fiber shifts can move absorption. Fix timing first - empty stomach, then a wait - before anyone doubles micrograms. Recheck in the usual window. Bring the latte habit to the visit.
Pia N., iron Pregnancy iron at dawn with 25 mcg because I vomit later.
Iron binds T4. Keep the four-hour idea even when pregnancy raised micrograms. Ask obstetrics for a timing map that survives nausea.
Olaug K., iron Prenatal iron with 25 mcg because pregnancy already changed the dose.
Iron binds T4. Keep the four-hour idea even when pregnancy raised the micrograms. Obstetrics still owns the TSH target. Do not combine swallows to save time.
Gudrun F., HRT Started estrogen last month. Still on 25 mcg. Exhausted.
Estrogen can raise T4 need. Book a TSH window. Do not double 25 mcg yourself. Confirm with the clinician who owns the lab. Icelandic emergency: 112.
Niels V., PPI Omeprazole moved to morning with Synthroid 25 to simplify.
Acid suppression plus a same-swallow T4 can lower uptake. Separate them and recheck TSH in the usual window. Do not double 25 mcg the same week. Icelandic emergency: 112.
Svana M., orlistat Xenical lunch, Synthroid dawn, TSH last checked eighteen months ago.
Recheck TSH after orlistat. Keep the dawn swallow and the meal capsules apart. Eighteen months is not a current window.
Ragnar T., orlistat Xenical started. TSH last year was fine on 25 mcg.
Last year is not this interaction. Recheck TSH after orlistat. Keep dawn T4 and meal capsules apart. See the orlistat orbit.
Helgi P., estrogen HRT month one, still 25 mcg, exhausted, wants 50 tonight.
Book a TSH window. Do not double yourself. Estrogen can raise T4 need. Hair and fatigue are not a kitchen titration. Bring the HRT start date so the locum does not invent an allergy.
Bjorn L., latte Soy latte every dawn with 25 mcg. Never works. Extra tablet?
Move the latte. Do not add a tablet. Coffee and soy sit on the absorption list. Resume the usual 25 mcg map. Tell the clinic at the next draw, not after a kitchen 50 mcg night.
Desk note Minimum TSH visit packet?
Exact swallow time, coffee delay, calcium/iron/PPI list, product manufacturer, biotin hold, last TSH date, pregnancy intent. Caelum educates. Ingrid does not titrate mcg by thread. Confirm with your clinician. Chest pain or severe palpitations: 112.