Is It OK to Take Herbal Supplements? Safety, Interactions, and What Works (2025 Guide)

• Sep, 5 2025
• 0

You want a straight answer: is it OK to take herbs? Yes-sometimes. For healthy adults with a clear goal, the right product, and no risky meds, many herbs are reasonable to try short term. The catch is simple: natural doesn’t mean harmless, and labels don’t always tell the whole story. Here’s the clear way to decide if an herb fits you, how to use it safely, and what actually has evidence behind it in 2025.

TL;DR

• Reasonable for many healthy adults to try, short term, at label doses-after checking for interactions and health conditions.
• Not OK if you’re pregnant or breastfeeding, have liver/kidney disease, upcoming surgery, or take narrow‑therapeutic‑index meds (warfarin, anti‑rejection, chemo, HIV, seizure meds).
• In Australia, pick products with AUST L, AUST L(A), or AUST R on the label; consider third‑party testing (USP, NSF, Informed Sport).
• Start one product at a time. Set a clear goal. Reassess in 4-8 weeks. Stop at any side effects.
• Some herbs have decent evidence (ginger for nausea, peppermint oil for IBS). Some are mixed (turmeric for joint pain). Some interact hard (St John’s wort with many meds).

When is it OK to take herbal supplements?

First, let’s be crystal clear: herbs are active chemicals. They can help, do nothing, or cause harm-just like any other bioactive product. The good news is you can make a safer call with a quick, practical filter.

It’s reasonable to consider herbal supplements if all of these are true:

• You’re an adult, generally healthy, and not pregnant or breastfeeding.
• You don’t have liver or kidney disease, bleeding disorders, or planned surgery within two weeks.
• You’re not on high‑risk meds like warfarin, lithium, digoxin, cyclosporine, tacrolimus, certain HIV meds, chemo, or seizure meds.
• You have a single, specific goal (e.g., reduce IBS cramps, ease mild joint pain, settle motion sickness) and a way to measure it (pain scale, symptom diary).
• You plan to try one product at a time, at label dose, for a set period (usually 4-8 weeks) and then reassess.

It’s not a good idea-or needs medical advice first-if any of these apply:

• Pregnant or breastfeeding. Most herbs lack strong safety data in these stages.
• Children and teens. Doses aren’t standardized, and data are thin.
• Liver or kidney disease. Many herbs are metabolised here; harm can sneak up.
• Upcoming surgery or dental procedures. Several herbs increase bleeding risk. Standard rule: pause herbs 2 weeks before procedures unless your doctor says otherwise.
• Mood disorders on medication. St John’s wort can trigger interactions and mood swings.
• Autoimmune disease or transplants. Immunomodulating herbs can be risky.
• Competitive athletes. Contamination and banned substances are a thing; use Informed Sport‑certified products and check WADA rules.

Live in Australia? Flip the bottle. If you see AUST L, AUST L(A), or AUST R, that means the product is listed or registered with the TGA. AUST L is low‑risk with safety and quality checks (claims are limited). AUST L(A) means some evidence for the claims was assessed. AUST R is for higher‑risk or stronger claims. No AUST number? That’s a red flag here.

One more reality check: the supplement world has had quality issues. A large JAMA review (2018) found hundreds of dietary supplements adulterated with pharmaceuticals over a decade, especially in weight‑loss and sexual enhancement categories. Australia’s TGA does regular recalls when products fail quality or contain undeclared drugs. So, shop like a skeptic.

Bottom line for this section: if you’re healthy, have a narrow goal, use a vetted product, and understand your meds, a careful trial can be OK. If you tick any high‑risk boxes, talk to your GP or pharmacist first.

How to choose and use them safely

Here’s the simple, no‑drama system I use personally and recommend to friends. It keeps you safe without turning this into homework.

1. Define the job to be done. What exact problem are you solving? “Fewer IBS cramps on weekdays” is clear. “Feel healthier” isn’t. Pick one goal and one measure you can track weekly.

2. Check if the herb actually fits your goal. Quick sources to consult: the NIH Office of Dietary Supplements fact sheets, Cochrane reviews, and TGA monographs/safety alerts. These are evidence‑based and not trying to sell you anything.

3. Scan for interactions with your meds and conditions. Big interaction magnets: St John’s wort (induces CYP3A4 and P‑gp-messes with many meds including the pill), ginkgo/garlic/ginseng (bleeding risk with anticoagulants), kava (sedation and liver risk), ashwagandha (thyroid/liver concerns), and grapefruit‑like effects from some botanicals. If you take warfarin, anti‑rejection, HIV, chemo, or seizure meds-get pharmacist clearance. For the contraceptive pill, avoid St John’s wort.

4. Pick a safer product.

   • In Australia, look for AUST L, AUST L(A), or AUST R on the label. No AUST number? Hard pass.
   • Prefer single‑ingredient, standardized extracts with the plant part and extract ratio stated (e.g., peppermint oil enteric‑coated 0.2 mL capsules; curcumin 95% standardized extract).
   • Avoid “proprietary blends” that hide amounts. You can’t dose what you can’t see.
   • Third‑party testing helps: USP, NSF, BSCG/Informed Sport for athletes.
   • Be extra cautious with imported “traditional” preparations that may contain heavy metals.

5. Use it like a scientist.

   • Start one product at a time. Keep everything else stable for 2 weeks.
   • Stick to label doses. More isn’t better-sometimes it’s liver tests.
   • Set a stop date (usually 4-8 weeks). If no clear benefit, drop it.
   • Track in a simple log: dose, time, symptom score, side effects.

6. Know your stop rules. Stop and seek care for rash, jaundice, dark urine, severe nausea/vomiting, mood changes, palpitations, bleeding/bruising, or any sudden new symptom. Report adverse events to the TGA via the online form-real‑world reports protect everyone.

Fast heuristics I live by

• One herb, one goal, one trial period.
• If it “cures everything,” it probably does nothing well.
• If you wouldn’t drink three cups of it as a tea, think twice about megadosing the capsule.
• Two weeks before surgery: pause all herbs unless your doctor says otherwise.
• Better sleep, gut health, and movement beat any capsule. Supplements are the side dish, not the main.

Buyer’s checklist (print this)

• AUST L / AUST L(A) / AUST R on label
• Single ingredient, standardized extract, clear dose
• No proprietary blend, no miracle claims
• Third‑party tested (USP/NSF/Informed Sport if relevant)
• Batch/lot number and expiry date present
• You’ve cross‑checked your meds and conditions
• Trial plan set: goal + measure + stop date

Evidence, interactions, and quick answers

Below are common herbs people ask me about, what the research says, and the big caveats. Snapshot ratings reflect summaries from sources like Cochrane reviews, the NIH ODS, and TGA safety communications as of 2025.

Where does this evidence come from? Cochrane reviews synthesize randomized trials; the NIH Office of Dietary Supplements publishes plain‑English fact sheets; the TGA monitors product quality and safety in Australia with public safety alerts. There are peer‑reviewed trials for specific herbs (e.g., peppermint oil for IBS, curcumin for OA). And yes, there are also many low‑quality studies-so lean on systematic reviews when you can.

Common pitfalls to avoid

• Stacking multiple herbs at once. If you feel off, you won’t know the culprit.
• Ignoring the pill. St John’s wort can reduce contraceptive effectiveness.
• Assuming “tea = safer.” Concentrated extracts and oils behave differently than teas.
• Using herbs to delay real care (e.g., chest pain, major mood shifts, rectal bleeding). Don’t.
• Buying the cheapest mega‑blend online with no AUST number. That’s a lottery you don’t want.

Mini‑FAQ

• Can I take herbs with antidepressants? Be careful. St John’s wort is a no with SSRIs/SNRIs/MAOIs. Kava and ashwagandha can add sedation. Talk to your prescriber.
• Do herbs detox the liver? No. Your liver and kidneys already do this. Some herbs can actually stress the liver.
• Are “AUST L(A)” products better? They’ve had some efficacy evidence assessed for their claims. It’s a useful signal, but still check dose, extract, and your risks.
• How long until I know if it works? Gut and sleep herbs: usually 2-4 weeks. Joint pain: 4-8 weeks. If nothing changes by your stop date, stop.
• Is organic safer? Fewer pesticides, potentially, but it says nothing about dose accuracy or contamination. Still look for testing and an AUST number.
• Can I drink alcohol with kava? Skip it. The combo adds sedation and liver risk.
• Do I need blood tests? If you’re on interacting meds or using a liver‑metabolized herb long term, ask your GP about baseline and follow‑up LFTs.
• What about kids? Don’t DIY. Paediatric dosing and safety are not well established for most herbs.

Next steps

• You’re a healthy adult with IBS cramps: Consider enteric‑coated peppermint oil with an AUST L number. Trial 4 weeks. Track pain/bloat. If reflux worsens, stop.
• You’re on warfarin and have knee pain: Don’t start turmeric/curcumin without a pharmacist review and INR monitoring plan. You have other pain options-ask your GP.
• You’re pregnant with morning sickness: Ginger often helps at modest doses, but run it past your midwife/doctor. Avoid blends and anything with vitamin A or unknown roots.
• You’re an endurance athlete: If you use any supplement, choose Informed Sport‑certified and keep a batch record. Contamination can trigger anti‑doping positives.
• You’re stressed and sleep is patchy: Fix sleep hygiene first (screens, caffeine, schedule). If you still want to try ashwagandha, pick a tested product, set an 8‑week stop date, and monitor mood and energy.
• You have recurrent UTIs: Cranberry may help with prevention, not treatment. If you’re on warfarin, check in with your care team first.

Why the caution? Apart from the interaction risks, quality varies. Even with decent regulation in Australia, not every product is equally good. Adverse event reporting to the TGA helps clean the market. Globally, regulators and medical journals (including a 2018 JAMA analysis) have flagged adulteration-especially in categories promising fast weight loss or sexual enhancement. If a claim sounds like a shortcut, it probably hides the bill.

A quick word on dosing

Stick to the label of a TGA‑listed/registered product. Extracts vary, so random internet doses don’t always apply to your bottle. For reference, practical trial windows: ginger (days), peppermint oil (2-4 weeks), turmeric/curcumin (4-8 weeks), St John’s wort (2-4 weeks), kava (2-4 weeks), ashwagandha (2-8 weeks). If you see no benefit by the end of that window, move on.

How doctors and pharmacists think about herbs

Most clinicians aren’t anti‑herb; they’re anti‑uncertainty. They need to know the exact product, dose, and timing to judge risk with your meds and conditions. Bring the bottle-or at least photos of the front and back labels-so they can check the AUST number, extract, and dose. It turns a vague chat into a useful safety review.

Safety reporting and recalls (Australia)

• Keep your batch/lot number and expiry. If anything feels off, you can report it.
• Search the TGA website for safety alerts and recalls by brand or AUST number.
• Pharmacists can lodge adverse event reports with you if you’re unsure how.

Key takeaways for 2025

• Evidence keeps shifting, but a handful of herbs consistently show benefit for specific problems (ginger for nausea, peppermint oil for IBS, curcumin for OA pain-small effect).
• Interaction‑heavy herbs (like St John’s wort) demand professional oversight or avoidance.
• TGA‑listed/registered status in Australia is a real safety signal. Use it.
• Your plan should include a goal, a metric, a time limit, and stop rules. No freewheeling.

This is general information, not personal medical advice. If your situation sits in any grey zone-or you’re on prescription meds-get a pharmacist or GP to sanity‑check your plan before you start.