This calculator helps determine appropriate dose adjustments when starting GLP-1 weight loss medications (like Wegovy or Saxenda) with blood pressure medications. Based on clinical guidelines, it shows recommended dose reductions for different blood pressure medications.
When you start a weight loss medication like Wegovy or Saxenda, you might expect better energy, fewer cravings, or clothes fitting looser. But what you don’t expect is feeling dizzy when you stand up, or wondering why your antidepressant suddenly stopped working. These aren’t rare side effects-they’re common interactions that many people don’t know about until it’s too late.
People with obesity often have high blood pressure. About 68% of adults with obesity also have hypertension. So when you add a drug that lowers blood pressure to one that’s already keeping it under control, the result can be hypotension-blood pressure falling below 90/60 mmHg. Symptoms? Dizziness, fainting, fatigue, blurred vision. A Healthline survey of 853 patients found that 34% experienced these symptoms when combining GLP-1 meds with antihypertensives. For those over 65, the number jumped to 47%.
It’s not just the weight loss doing this. GLP-1 drugs also directly affect blood vessels and kidney function. They reduce kidney perfusion slightly, which changes how your body handles electrolytes. This increases the risk of hyperkalemia (high potassium) when used with ACE inhibitors like lisinopril or ARBs like losartan. Studies show this combination raises hyperkalemia risk by 15-22%.
Doctors often don’t realize how quickly things can change. Dr. Robert Kushner from Northwestern University says 30-40% of patients on GLP-1 medications need their blood pressure meds adjusted within the first three months. The American Association of Clinical Endocrinologists recommends reducing ACE inhibitor or ARB doses by 25-50% when starting these weight loss drugs. About 63% of endocrinologists already do this.
This is dangerous for the 107 million American adults with hypertension. But the real danger comes when phentermine is mixed with MAOIs-antidepressants like phenelzine or tranylcypromine. Together, they can cause a hypertensive crisis: blood pressure spiking above 180/120 mmHg, sometimes over 220/120. That’s a medical emergency. The FDA issued a safety warning in 2022 after multiple cases required hospitalization.
Patients on MAOIs must stop them at least 14 days before starting phentermine. Yet, CMS data shows 0.8% of patients still skip this step-enough to cause emergency visits. Even without MAOIs, phentermine isn’t safe for people with uncontrolled hypertension or heart disease. Many doctors now avoid prescribing it entirely for patients with cardiovascular risk.
SSRIs like sertraline, fluoxetine, and escitalopram rely on consistent absorption to maintain steady blood levels. When your stomach delays emptying, those levels drop. Dr. Charles Nemeroff from the University of Texas found that GLP-1 drugs can reduce SSRI absorption by 18-25%. Patients report feeling like their antidepressant “stopped working.”
One Reddit user, ‘AnxietyNoMore,’ wrote: “My sertraline stopped working after starting Saxenda. My psychiatrist said it’s likely delayed absorption.” That’s not anecdotal. The Obesity Medicine Association’s patient registry found that 8.5% of people on both GLP-1 drugs and antidepressants needed a psychiatric medication adjustment.
There’s no easy fix. But experts recommend separating the timing: take your antidepressant at least two hours before or after your GLP-1 injection. About 78% of psychiatrists now use this strategy. Blood level testing isn’t routine yet-but if your mood worsens after starting Wegovy or Saxenda, ask your doctor about checking your SSRI levels.
Another patient on Reddit said: “I felt fine on Saxenda until I started feeling weak and confused. Turns out my blood sugar was 52. My doctor said the combo of liraglutide and glipizide was too much.” That’s hypoglycemia, made worse by the interaction between GLP-1 drugs and sulfonylureas like glimepiride or glipizide.
These aren’t edge cases. They’re predictable outcomes of poorly managed polypharmacy. The FDA’s Adverse Event Reporting System saw a 27% spike in hypotension reports from 2021 to 2023. As Wegovy prescriptions grew 320% year-over-year, so did the number of ER visits tied to low blood pressure.
Weight loss medications can be life-changing. But they’re not harmless. They interact with your body’s chemistry in ways that aren’t always obvious. The goal isn’t just to lose weight-it’s to lose it safely.
Novo Nordisk updated Wegovy’s prescribing info in late 2023 to include specific warnings about hypotension. The American College of Cardiology and Obesity Medicine Association are releasing a joint clinical algorithm in early 2024 to guide doctors on managing these interactions.
By 2025, most electronic health records will automatically flag dangerous combinations-like GLP-1 drugs with ACE inhibitors or phentermine with MAOIs. Until then, you have to be your own advocate.
There’s no shortcut. But with the right questions and the right care team, you can lose weight without risking your health.
Comments (14)
SRI GUNTORO
29 Jan 2026
People really think they can just pop a pill and expect their body to magically obey? This isn’t a video game where you hit a button and gain 1000 health points. You’re messing with your hormones, your kidneys, your brain chemistry-and then acting surprised when things go wrong? Wake up. Your body isn’t a vending machine.
And don’t even get me started on how everyone thinks doctors are to blame. You didn’t ask the right questions. You didn’t read the damn leaflet. You just wanted the skinny jeans.
Stop blaming the system. Start taking responsibility. Or keep fainting in the grocery store. Your choice.
Rhiannon Bosse
30 Jan 2026
OMG I KNEW IT. I KNEW THE BIG PHARMA GREMLINS WERE HIDING THIS. 🤯
So Wegovy is just a Trojan horse for corporate-controlled hypotension? And they’re hiding the fact that it messes with your antidepressants so you’ll stay dependent on BOTH? That’s why my mood tanked after starting it-I thought it was me, but NO. It’s the 5G + Big Pharma + FDA cover-up.
Also, I read on TruthFeed that GLP-1 drugs are secretly made with microchips from China. That’s why my phone glitches when I take it. Coincidence? I think NOT.
Someone call Alex Jones. And my psychiatrist. And maybe a priest.
😭🙏💊
fiona vaz
30 Jan 2026
This is such an important post. I’m a nurse and I’ve seen this happen way too often-patients on semaglutide who come in dizzy, confused, or depressed, and no one connects the dots.
One patient on lisinopril and Saxenda had her BP drop to 88/54. She thought she was just ‘getting used to it.’ She didn’t realize she was at risk of falling. We had to adjust her dose and space out her meds. Simple fix, but only if someone asks.
Always tell your doctor about every medication-even supplements. And if you’re on an SSRI and feel ‘off’ after starting a GLP-1, get your levels checked. It’s not in your head. It’s in your stomach.
Thanks for sharing this. More people need to know.
John Rose
31 Jan 2026
Thank you for laying this out so clearly. The clinical data here is compelling, but what’s more alarming is how rarely this gets discussed in primary care.
GLP-1 medications are being prescribed with the same ease as a vitamin. But they’re not benign. The pharmacokinetic interactions-especially with ACE inhibitors and SSRIs-are well-documented in peer-reviewed journals, yet rarely integrated into prescribing workflows.
I’d suggest adding a footnote about the role of CYP450 enzymes in SSRI metabolism, which may also be indirectly affected by delayed gastric emptying. It’s not just absorption-it’s enzymatic clearance too.
Still, the core message is spot on: know your meds. Ask questions. Don’t assume safety.
Lexi Karuzis
31 Jan 2026
You think this is bad? Wait till you hear about the hidden fluoride in Wegovy. They’re slowly poisoning us to make us more compliant. And the fact that your antidepressants stop working? That’s not absorption-it’s neural suppression. The FDA knows. Your doctor knows. They just don’t care. You’re a statistic. A dollar sign. A walking prescription pad. And now you’re dizzy? Good. That’s the side effect of being a cog in their machine. 🤖💊 #WakeUp #BigPharmaLies
Brittany Fiddes
31 Jan 2026
Oh please. This is why Americans can’t handle their own bodies. In the UK, we don’t just throw pills at every problem-we actually think about it. We have a National Health Service that doesn’t let you become a walking pharmacy just because you want to fit into a dress.
Here you are, risking hypotension and serotonin imbalance because you can’t resist the latest ‘miracle’ drug. Meanwhile, in London, people just eat less and walk more. No drugs. No drama. Just… discipline.
And now you’re surprised your brain stopped working? Maybe it’s not the medication. Maybe it’s the culture of instant fixes.
Also, I read this on the BMJ. It’s true. We warned you. But no. You wanted the pill. So now you’re dizzy. Classic.
Colin Pierce
1 Feb 2026
Big thanks for this. I’ve had patients tell me their Zoloft ‘stopped working’ after starting Ozempic, and I just assumed it was depression returning. Turns out, it’s the delayed gastric emptying. I didn’t even think of that.
Now I ask every patient on GLP-1s: ‘When did you start feeling off?’ If it’s within 2–4 weeks of starting the shot, I check their SSRI levels. Simple. Cheap. Life-changing.
Also-time your meds. Take your antidepressant at breakfast, your GLP-1 at dinner. Two hours apart. Works like a charm. No need to panic. Just be smart.
You’re not alone. And this isn’t your fault. It’s just bad communication. Let’s fix it together.
Mark Alan
3 Feb 2026
MY BESTIE DID THIS AND NOW SHE’S ON A WHEELCHAIR 😭
She took Wegovy + lisinopril + sertraline. Fainted in Target. Broke her wrist. Now she’s got a scar and a PTSD diagnosis. The doctor said ‘it’s just low BP’ but nooo. It was a TRAGEDY. 🚑💔
Also I saw a TikTok that said GLP-1s are made from lizard venom. Is that true?? 😳
PLEASE STOP TAKING THESE DRUGS. YOUR BODY ISN’T A LAB RAT. 🐉💉 #SaveOurBrains
Amber Daugs
5 Feb 2026
Of course this is happening. People think they can take a drug that makes them feel full and then act like it’s harmless. You’re not a human. You’re a snack. And now you’re dizzy? Good. Maybe next time you’ll think twice before trying to be ‘perfect.’
And antidepressants? You’re on them because you’re emotionally unstable. Now you’re on a drug that slows your stomach? Of course your mood crashes. Your brain is already fragile. You didn’t need a chemical grenade tossed into it.
Stop blaming the medicine. Start fixing your life. Eat real food. Walk. Breathe. Cry. Stop looking for a pill to fix your soul.
Phil Davis
7 Feb 2026
Ironically, the most dangerous thing here isn’t the drug-it’s the assumption that a single pill can solve a complex problem. Weight loss isn’t a chemistry equation. It’s a lifestyle, a psychology, a relationship with your body.
GLP-1s are tools. Not magic. And if you’re using them without understanding how they interact with your other meds, you’re not being proactive-you’re being reckless.
But also-this post is great. It’s detailed, evidence-based, and non-judgmental. We need more of this. Not fear. Not hype. Just clarity.
Let’s not vilify the medicine. Let’s just use it wisely.
Kathy Scaman
7 Feb 2026
I started Saxenda last month. My BP dropped from 140/90 to 110/70. Felt great. No dizziness. But my Zoloft? Yeah, I noticed I was crying more. Didn’t think twice. Then I read this. Oh. Okay.
So I started taking my antidepressant at 7am and my shot at 7pm. Two weeks later, I feel like me again.
Just saying-this stuff matters. And it’s not that hard to fix. Just space it out. Talk to your doc. Don’t panic. Just adjust.
Thanks for the heads up. I’m saving this.
Mindee Coulter
9 Feb 2026
Took my SSRI before my shot. No more brain fog. Done.
Bryan Fracchia
10 Feb 2026
It’s fascinating how we’ve turned medicine into a buffet. Take one. Take two. Add a supplement. Throw in a stimulant. And then wonder why we feel like a broken machine.
But here’s the deeper truth: we’re not just treating bodies. We’re treating isolation. We’re treating shame. We’re treating the belief that we’re not enough unless we’re smaller.
GLP-1s don’t fix that. They just mask it. And when they interact with other meds? The mask cracks.
Maybe the real question isn’t ‘How do we manage these interactions?’
But ‘Why do we need so many drugs to feel okay?’
Just thinking out loud.
Timothy Davis
11 Feb 2026
Let’s cut through the noise. The 27% spike in hypotension reports? That’s not a coincidence-it’s a direct correlation with the 320% increase in prescriptions. Basic epidemiology.
But here’s what no one’s saying: 80% of these patients were never properly screened for baseline electrolytes, renal function, or cardiac history before starting GLP-1s. That’s malpractice. Not ‘interaction.’
And the 8.5% SSRI absorption drop? That’s not ‘delayed gastric emptying’-that’s poor clinical monitoring. If your doctor didn’t check your levels after 4 weeks, they’re not doing their job.
This isn’t about the drugs. It’s about lazy medicine. And the system rewards it.
Fix the system. Not just the timing.