Ro weight loss side effects come from the medicine, not Ro itself. Ro prescribes GLP-1 medicines: Wegovy, Zepbound, Foundayo and Ozempic. Their most common side effects are nausea, diarrhea, vomiting, constipation and stomach pain, mostly when you start or raise the dose. Serious risks are less common but real, so you'll want to know the warning signs.
Ro's membership includes side-effect management and dose-adjustment support from its providers, plus unlimited messaging. That doesn't make side effects less likely, but it means someone is there to help you adjust.
The RX Index is the independent GLP-1 decision resource that scores telehealth providers and treatment paths on clinical legitimacy, care quality, transparency, access, and cost, so readers can choose the path that fits their situation.
RX Index Decision Verdict: Side effects on Ro are the same as with any provider that prescribes these brand-name medicines. What Ro adds is follow-up support.
- Best for: people who want an online provider to help them work through stomach side effects and dose changes.
- Not ideal for: anyone with a personal or family history of medullary thyroid cancer or MEN 2, and people who want in-person care if side effects get bad.
- The factor that matters most: which medicine and dose you're on. Side effects rise with higher doses, and they're most common in the first months.
Ro side effects at a glance
| Medicine on Ro | Form | Most common side effects (FDA label) | Worth knowing |
|---|---|---|---|
| Wegovy pen | Weekly shot | Nausea, diarrhea, vomiting, constipation, stomach pain | Also headache and tiredness |
| Wegovy HD (7.2 mg) | Weekly shot | Nausea, vomiting, skin sensitivity or burning feelings (dysesthesia), constipation | Dysesthesia was much more common at 7.2 mg |
| Wegovy pill | Daily tablet | Similar to the Wegovy shot, per the label | Studied at 25 mg |
| Zepbound (pen or KwikPen) | Weekly shot | Nausea, diarrhea, vomiting, constipation, stomach pain, indigestion | Injection site reactions; can make birth control pills less effective |
| Foundayo | Daily tablet | Nausea, constipation, diarrhea, vomiting, indigestion, stomach pain | Can make birth control pills less effective; some drug interactions |
| Ozempic | Weekly shot | Nausea, vomiting, diarrhea, stomach pain, constipation | Approved for type 2 diabetes, prescribed off-label for weight loss |
See which Ro medicine fits your health history (sponsored affiliate link, opens in a new tab)
How common are side effects on each Ro medicine?
These are the numbers reported in each drug's FDA label from its main weight-loss trials, at the highest dose studied.
| Medicine (dose) | Nausea | Diarrhea | Vomiting | Constipation | Stopped due to side effects |
|---|---|---|---|---|---|
| Wegovy shot (2.4 mg) | 44% | 30% | 24% | 24% | 6.8% |
| Wegovy HD (7.2 mg) | 39% | Not listed in that table | 22% | 20% | 5% |
| Zepbound (15 mg) | 28% | 23% | 13% | 11% | 6.7% |
| Foundayo (17.2 mg) | 35% | 25% | 24% | 24% | 10% |
Placebo rates in the same trials were much lower: for example, nausea was 16% (Wegovy), 13% (Wegovy HD), 8% (Zepbound) and 10% (Foundayo).
Two cautions. First, these were different trials with different people, so don't treat this as a head-to-head ranking. Second, lower doses usually had lower rates. For example, nausea on Zepbound was 25% at 5 mg, and on Foundayo it was 26% at 5.5 mg.
The labels for Zepbound and Foundayo say stomach side effects were most common while the dose was going up and then decreased over time. For a drug-by-drug view, see our GLP-1 side effects comparison chart.
Which side effects are specific to certain Ro medicines?
- Skin sensitivity on Wegovy HD. Dysesthesia means unusual skin feelings, like burning, tingling or sensitivity. It was reported by 22% of people on 7.2 mg, compared with 6% on 2.4 mg. More in our Wegovy HD side effects guide.
- Injection site reactions on Zepbound. Redness, itching, bruising or pain where you inject happened in up to 8% of people.
- Birth control pills on Zepbound and Foundayo. Both labels say these medicines can make birth control pills less effective. Zepbound's label advises a non-oral method or a backup barrier method for 4 weeks after starting and after each dose increase. Foundayo's label says 30 days. See our Foundayo side effects guide.
- Hair loss. Hair loss was listed for all of these weight-loss medicines, at 6% or less at the highest doses. Read more in GLP-1 hair loss.
- Diabetic eye problems. The labels say people with type 2 diabetes and a history of diabetic eye disease (retinopathy) should be monitored.
What are the serious risks?
All of Ro's GLP-1 medicines carry a boxed warning, the FDA's most serious kind, about thyroid C-cell tumors seen in rodent studies. For Wegovy, Ozempic and Zepbound, the drugs caused these tumors in rodents, and it isn't known if they do in people. For Foundayo, the label says the drug isn't active in rodents and didn't cause tumors in them, but similar medicines did, and the risk to people hasn't been determined.
Do not use these medicines if you or a family member has had medullary thyroid cancer (MTC), or if you have Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
The labels also warn about:
- Pancreatitis (inflammation of the pancreas)
- Gallbladder problems, including gallstones
- Low blood sugar if you also take insulin or a sulfonylurea
- Kidney problems from dehydration, often after vomiting or diarrhea
- Serious allergic reactions
- Food or liquid getting into the lungs during anesthesia or deep sedation
- Harm to a developing baby, so the medicine is stopped when pregnancy is found (Wegovy's label says to stop at least 2 months before a planned pregnancy)
Don't combine these medicines with each other or with another GLP-1 medicine.
When should you call your Ro provider or get help?
| What you notice | What to do |
|---|---|
| Mild nausea, constipation or diarrhea after starting or raising a dose | Message your Ro provider. Ask about pacing your dose increases. |
| Vomiting or diarrhea that won't stop, or you can't keep fluids down | Contact your provider the same day. Dehydration can hurt your kidneys. |
| Severe stomach pain that won't go away, with or without vomiting or pain in your back | Get medical care right away. This can be a sign of pancreatitis. |
| Pain in your upper stomach, fever, yellow skin or eyes, or clay-colored stools | Contact a provider right away. These can be gallbladder signs. |
| A lump or swelling in your neck, hoarseness, trouble swallowing or shortness of breath | Tell your provider. These can be thyroid tumor symptoms. |
| Swelling of your face or throat, trouble breathing, or a fast heartbeat | Call 911 or get emergency care. This can be a serious allergic reaction. |
| You're scheduled for surgery or a procedure with sedation | Tell your provider and the surgical team that you take a GLP-1. |
Ro's own safety page says to call 911 or get immediate medical attention in an emergency. Ro is an online service, so it isn't your emergency care.
How does Ro help with side effects?
Per Ro, the membership includes:
- Side-effect management and titration support (help pacing your dose)
- Unlimited messaging with your provider
- Weight tracking and dose logging
- One-on-one health coaching
Ro's own guide suggests starting at a low dose and moving up slowly, staying hydrated, eating smaller and more frequent meals, and asking your provider about medicine for nausea.
What we couldn't confirm: how fast Ro providers reply to messages, and whether they'll prescribe anti-nausea medicine. Ro describes the support but doesn't publish response times.
Comparing your options or checking if insurance can cover the medicine? Ro can check coverage for the Wegovy pen, Zepbound pen and Ozempic.
Check your GLP-1 coverage with Ro (sponsored affiliate link, opens in a new tab)
Find the GLP-1 path that fits your health
Who should think twice about Ro's GLP-1 medicines?
| Your situation | Our take |
|---|---|
| Personal or family history of MTC, or you have MEN 2 | Don't use these medicines. |
| Had pancreatitis or gallbladder problems | Tell the Ro provider first. They'll weigh the risk. |
| Take insulin or a sulfonylurea for diabetes | Your diabetes medicine may need adjusting to avoid low blood sugar. |
| Use birth control pills and are considering Zepbound or Foundayo | Plan for backup birth control during the first weeks and after dose increases. |
| Pregnant or trying to get pregnant | Talk to your provider before starting. The labels say to stop when pregnancy is found. |
| Prone to strong nausea | Ask about the slowest dose plan. See our guide to GLP-1 nausea and the GLP-1s with the fewest side effects. |
What we actually verified
- Read the current FDA prescribing information for Wegovy (revised June 2026), Zepbound (revised August 2026), Foundayo (revised July 2026) and Ozempic (revised May 2026), and copied side-effect rates from their trial tables.
- Opened Ro's weight-loss page, pricing page and Wegovy page on October 31, 2026, to confirm which medicines Ro offers and what its membership includes.
- Read Ro's safety page and Ro's guide to Ozempic for weight loss for its side-effect advice.
Provider-stated, not verified by us: what Ro's side-effect support includes in practice. What we couldn't confirm: Ro's provider reply times. Trial rates come from different studies and aren't a direct comparison.
Frequently asked questions
What are the side effects of Ro weight loss medicine?
The most common are nausea, diarrhea, vomiting, constipation and stomach pain. They're most likely in the first months and after dose increases. Serious but less common risks include pancreatitis, gallbladder problems and allergic reactions.
Does Ro itself cause side effects?
No. Ro is a telehealth service. Side effects come from the medicine your Ro provider prescribes, and they're the same as if another doctor prescribed it.
Which Ro medicine has the fewest side effects?
There's no head-to-head answer. In each label's main trials at the top dose, nausea was reported by 44% on the Wegovy shot, 39% on Wegovy HD, 28% on Zepbound and 35% on Foundayo, but the trials were different. Your dose and health history matter more.
How long do side effects last on Ro's GLP-1s?
The Zepbound and Foundayo labels say stomach side effects were most common while the dose was increasing and decreased over time. Ro says side effects tend to be worst when starting or moving up a dose.
Does Ro help with nausea?
Ro says its membership includes side-effect management and dose-adjustment support, and its guide suggests asking your provider about medicine for nausea. We couldn't confirm whether Ro providers prescribe it.
Can Ro's weight loss medicine affect birth control?
Zepbound and Foundayo can make birth control pills less effective. Their labels advise a non-oral method or a backup barrier method after starting and after each dose increase.
Who shouldn't take Ro's GLP-1 medicines?
Anyone with a personal or family history of medullary thyroid cancer (MTC) or with MEN 2, anyone who's had a serious allergic reaction to the medicine, and people who are pregnant.
Still not sure which GLP-1 path fits you? Take The RX Index's free Find My GLP-1 Path quiz — about 2 minutes, no signup.
Compare GLP-1 paths for your situation
Sources
- Wegovy prescribing information (Novo Nordisk, revised June 2026; checked October 31, 2026)
- Zepbound prescribing information (Eli Lilly, revised August 2026; checked October 31, 2026)
- Foundayo prescribing information (Eli Lilly, revised July 2026; checked October 31, 2026)
- Ozempic prescribing information (Novo Nordisk, revised May 2026; checked October 31, 2026)
- Ro: Weight loss (checked October 31, 2026)
- Ro: Weight loss pricing (checked October 31, 2026)
- Ro: Wegovy pen (checked October 31, 2026)
- Ro: Important safety information for GLP-1s (checked October 31, 2026)
- Ro: Ozempic for weight loss (checked October 31, 2026)