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Our Most Frequently Asked Questions.

1. How does iontophoresis work?

Tap water iontophoresis (TWI) treats hyperhidrosis using a mild electrical current running through water to deliver ions into the body. That process blocks the skin ducts to create a safe (and well-documented) treatment for hyperhidrosis, a condition that causes excessively sweaty hands or palms, feet, or underarms.

And by “well-documented,” we mean that tap water iontophoresis has been researched and trusted as a go-to hyperhidrosis treatment for more than 40 years. And it’s one of the most prevalent treatments for hyperhidrosis in Europe, where hyperhidrosis has been much more recognized, diagnosed, and treated.

2. How long does treatment last?

Think of it as a workout or a type of physical therapy; you get the results based on how diligent you are in doing your exercises or therapy sessions.

Here’s the schedule that works well for most people:

  1. Initial Treatment Schedule. Start with ten 15-minute treatment sessions (sessions should be about 24 hours apart).
  2. Maintenance Schedule. The effects are iontophoresis are reversible, but just one or two treatments per week typically keep the symptoms away.

Of course, no two cases are exactly alike, so feel free to make adjustments to your treatment schedule. For example, you may find that more or less than the recommended 15 minutes per session works better for you.

3. Do your hyperhidrosis treatments hurt?

No. In fact, most people experience very little, if any, “discomfort.”

And there are two reasons for that:

First, our devices have built-in Anti-Shock Electronics (ASE©). Though some iontophoresis devices can deliver an uncomfortable shock when removing your skin from the water, every Hidrex USA iontophoresis device has built-in Anti-Shock Electronics, which virtually eliminates that possibility.

It is important to note that ASE©  is only enabled while the device is ON, so we recommend removing your hands and feet from the water or the pads & electrodes assembly from your underarms or face BEFORE turning off the device.

Second, our devices have settings that put you in control of your comfort. Should you experience any amount of discomfort, the DP450 Underarms allows you to make some adjustments to increase comfort, but those adjustments may reduce the effectiveness of your treatment.

And thanks to its revolutionary variable pulsed current (VPC) technology, the DVP1000 Hands & Feet and the DVP1000 Ultimate allow you to maximize comfort without sacrificing effectiveness. With the DVP1000, maximum comfort and maximum effectiveness are a “both-and,” not an “either-or.”

4. Are your iontophoresis machines safe?


Tap water iontophoresis is considered a safe practice. As result, it’s no surprise that our devices are FDA-cleared for sale and use in the United States.

5. Why are some competing devices cheaper?

You can find iontophoresis machines for half what you’ll pay for one of ours. In fact, companies who offer cheap alternatives pop up all the time.

Obviously, we’re biased, but here’s what you get when you treat hyperhidrosis with a Hidrex USA iontophoresis machine:

  • An iontophoresis machine that works as advertised. Clinical studies have shown that Hidrex USA devices reduce sweat 100% of the time. And that’s great. But the question is, “Are our customers happy with it?” According to Shopify, 20% (and 30% during holiday seasons) of online purchases are returned. But the Hidrex USA DP450 has a return rate of only 4%. And most of those are exchanges for the Hidrex USA DVP1000, which is returned just 1% of the time. And as you can imagine, we’re quite happy to have happy customers. 😉
  • An iontophoresis machine that’s built to last. Many iontophoresis machines are made in China from subpar components. In stark contrast, Hidrex USA products are designed and manufactured in Germany. As is the norm with German engineering, Hidrex USA devices are made from top-notch components following extensive research. Oh, and they’ve been in production for 40+ years.
  • An iontophoresis machine that’s FDA-cleared. Many of our competitors have not gone through the costly process of becoming FDA-approved/cleared.
  • An iontophoresis machine that’s safe to use. Some iontophoresis devices are made without safety circuits to protect the user. They’re just voltage regulators with electrodes!

6. Why is FDA clearance important?

There are a number of iontophoresis devices available on the Internet. And only a very small number of them are FDA approved/cleared. FDA-approved/cleared ensures that the device has been designed and proven to be safe and effective for its intended use. Hidrex USA TWI devices are CE Marked (as they are manufactured in Germany) and FDA-cleared (as they are distributed from the U.S.).

Of course, there are other good and approved devices available, but we are concerned for the safety of users who have purchased some of the new devices that have appeared in the last couple of years. Many of them have no approval from their country’s (or any country’s, for that matter) health department and have no chance of it being approved even if submitted.

There is one device in particular that is not really a device at all; it is just an A/C wall adapter with selectable voltages and some electrodes (YIKES!). It has no protective circuits or other mechanisms in place in the case of a failure of the A/C adapter. And that’s both careless and alarming.

Because tap water iontophoresis device mixes water with electricity, Hidrex USA operates under the assumption that FDA approval or equivalent matters to you.

7. Who should NOT use Hidrex USA devices?

Unless otherwise directed by your physician, you should NOT use Hidrex iontophoresis machines if you:

  • Have a cardiac pacemaker;
  • Have an ICD (implantable cardioverter/defibrillator);
  • Are pregnant;
  • Have a metal-containing intrauterine device (IUD);
  • Have metallic implants within the current path (arm or leg);
  • Have large skin defects/wounds that cannot be covered with petroleum jelly;
  • Have impaired sensibility in your hands or feet (e.g. patients with polyneuropathies);
  • Have potentially malignant lesions, acute localized infections, skin eruptions, or swollen, broken, or inflamed areas;
  • Have an area of your body where sensation is absent or impaired;
  • Apply electrical current through or across the chest, brain, or sinuses;
  • Have suspected or diagnosed heart problems or epilepsy.

8. Can I get help from a human—for free?


We want the same thing you want—your freedom from excessive sweat!

So, if you don’t find the answers you want in our support documentation (or if you’d rather just ask a human), then feel free to call and/or email us.

If you’re not getting results quickly, it’s helpful for us to know how you have been treating, so, if you have it, email us a log of your treatment sessions. You can email your treatment log to customer.service@hidrexusa.com.

9. If I buy now, can you help me get an Rx?

Yes. To get an Rx, ask your doctor for a prescription for “Hidrex device” or “iontophoresis machine.” Or, if they prefer, they can download and complete this form.

10. Will my insurance company reimburse me?


Because all Hidrex USA devices are FDA cleared, many insurance companies issue reimbursements for Hidrex USA iontophoresis machines. Want to know more? See our insurance reimbursement guide.

11. Can I use my HSA or FSA card?


Hidrex iontophoresis machines are classified as a medical product and is therefore eligible to be purchased with a Health Savings Account or Flexible Spending Account debit card.

12. What is direct current?

Direct current simply means that the voltage is being transmitted 100% of the time.

13. What is pulsed current?

Conventional or traditional pulsed current means that the current alternates its transmission between ON and OFF for equal lengths of time. The pulse and the pause are the same duration. For example, 50 microseconds ON and then 50 microseconds OFF, and then repeat.

14. What is variable pulsed current?

Variable pulsed current is a type of hybrid current between traditional pulsed current and direct current and is available ONLY on the Hidrex DVP1000. It allows for the ON part of the cycle (the pulse) to run longer than the OFF part of the cycle (the pause) in 10% increments (for example, ON 70%, OFF 30%). This allows for more effective treatment AND a better comfort level. It is customizable to the individual based on their preferences and treatment tolerance levels. This is especially critical in hand, underarm, or face treatments where the skin is more sensitive, or for the treatment of children. The Variable pulsed current measurement is defined as a pulse width. Let’s look at how this compares to traditional pulsed current and direct current:

  • A pulse-width of 50% is equivalent to traditional pulsed current operation. In this case, the pause is as long as the pulse.
  • A pulse-width of 100% (no pause) is equivalent to direct current operation.

With increasing percentages of the pulse-width, the length of the pulse is increased and the length of the pause is decreased accordingly. Due to the shorter pause, more current than traditional pulsed current is applied. The variable pulse-widths of the Hidrex DVP1000 allow adjustments in 10% increments between the more sensitive pulsed current and the stronger direct current.

15. Which type of current is best?

Direct current (DC) is inherently more efficient because the user is getting current or treatment ALL of the time. The trade-off is that you can feel it more.

Pulsed current (PC) can be almost imperceptible at certain voltages, which tends to work well for more sensitive applications like underarms, hands, and in the treatment of children. But because lower voltage is less efficient, pulsed current treatment sessions typically last longer.

Variable pulsed current (VPC) (available only with the DVP1000 Hands & Feet & DVP1000 Ultimate iontophoresis machine packages) is a hybrid of direct and pulsed current that allows users to maximize comfort and efficiency.

So, which type of current works best? Most users prefer the variable pulsed current of the DVP1000, but in the end, you should utilize the current that works best for you.

16. Should I switch sides of the tray halfway through treatment?

Switching which body area goes to which side of the tray is called polarity switching, and there are some misconceptions about it, so let’s discuss it so you can do it correctly IF you even do it at all. Polarity switching (for example, putting your right hand in the tray with the red electrode or the positive side and your left hand in the black or negative side, and then switching them after a given time period) has some possible upsides as well as downsides. It is proven that the positive/red electrode is slightly more powerful than the negative/black electrode, so theoretically, if one hand/foot always stayed in the positive side, it would get results first.  The hand/foot in the negative side would eventually catch up after several treatments. However, if you are treating at a high dosage, which is much more likely when you are treating with a Variable Pulsed Current that the DVP1000 offers, the hand/foot in the negative side is getting treated at a level that does not make it lag behind the positive side, so there is typically not a need to practice polarity switching in this case. Because of the higher/faster efficacy in the positive side, many physicians were taught many years ago to recommend polarity switching and some manufacturers have built into their device a feature to switch polarity after x number of minutes into a treatment session.  For reasons discussed below, Hidrex products do not have polarity switching features and do not recommend switching within a given treatment session. On the downside, many users that have done polarity switching halfway through a treatment session report an intense and very uncomfortable feeling immediately after the switch due to the quick reversal of the electrical current.  For that reason, we recommend if you DO practice polarity switching, it is better to switch every treatment rather than in the middle of treatment (for example, treat right hand on red and left hand on black on Monday, and then right hand on black and left hand on red on Tuesday.  That way, you avoid the negative affect of this treatment.  This is the primary reason Hidrex does NOT make Polarity Switching as a feature of the device. Whether you practice polarity switching is a personal choice.  On one hand, it may possibly have the hands reach dryness more equally.  On the other hand, it is a bit tedious to remember or log which side to do every treatment, and it may not even be necessary. On occasion, we do have customers that we advise to practice polarity switching, so it can be necessary in some cases. The bottom line is, if you do decide to switch polarity, we recommend switching every treatment not halfway through treatment, to get the possible benefit of it without the possible discomfort.

17. What to do about discolored electrodes?

It is normal for at least one of the electrodes to become discolored after just a couple of uses. Typically, the black electrode (the negative side) gets discolored faster or more. The discoloration does NOT affect efficacy. What DOES affect efficacy is calcium or mineral deposits that accumulate over time due to water hardness. Every 3-6 months (depending on water hardness), the electrodes should be soaked in a half water/half vinegar solution overnight and then scrubbed and rinsed to prevent loss of efficacy. We often get calls or emails from customers about a year after purchase that their device is not as effective. A good cleaning always does the job.

18. My device didn't go up to the preset voltage—is it defective?

It is very rare for a device to be defective or become defective. We occasionally get calls or emails from new customers that are using the device for the first time that state that the voltage does not go up as high as they set it at, or that it dropped down a bit in voltage after going to the set voltage. (for example, they set the voltage at 35, and it goes to 35 temporarily and then drops to 29V. Or it never even gets to 35 and just stops at 29). When this happens, it is most likely that the Current Limitation feature has been activated (see page 18 of the manual). This happens when a person’s body electrical resistance is very low. The voltage will only increase up to a certain point until the body resistance increases, which will happen with subsequent treatments as a person becomes “drier”.  As your resistance increases, then higher voltages can be reached. If a user experience this, it is important to remember that the device saves the settings as it was last used if it is in a profile setting, so it is recommended that the user manually increase the voltage to a higher point than it was last used at to make sure the device can “try” to go higher on the next session.  For example, using the example above, if the device stopped at 29V, and the user previously set it at 35V, then the next time the device is turned on, it will only go to 29V unless the user again increases it higher to 30 or more.

19. Should I feel more current on one side than the other?

There is a positive side (the red) and a negative side (the black) of the current flow. It is very common for a user to feel the current on one side more than the other. Interestingly, although the positive side is clinically proven to be slightly more effective, which is why some users like to practice switching sides or “polarity switching”, there is no rule or consistent reporting that the positive side is felt more.  Some users feel the positive side more and others feel the negative side more. This is normal and okay.

20. My device is less effective than normal—is it defective?

It is very rare for a device to be defective or become defective. In almost all cases, the reason for a device becoming less effective is due to the electrodes needing a good cleaning. Mineral deposits accumulate on the electrodes (metal plates) and need to be removed from time to time. There are many ways to clean these effectively. One of the easiest is to soak the electrodes in a half water/half vinegar solution overnight and then scrub them off the next day with a towel and then rinse. This almost always returns the device to its original efficacy level.

21. Can I get a refund?

Every Hidrex USA iontophoresis machine comes with a 60-day money-back guarantee. So, if you’re not completely satisfied with your purchase, you can return it within 60 days for a full refund. We just ask that you cover the return shipping costs.

22. Do your devices have a warranty?


Every Hidrex USA device comes with a five-year warranty that covers the operation of TWI modules only (accessories or consumables are not warrantied). We will repair or replace the device at no charge unless the failure of the device is due to abuse, mishandling, or any other apparent external damage.

Please note that devices sold prior to June 1, 2019, have a three-year warranty.

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Suite 350-384
Austin, TX 78738

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