Iontophoresis is a technique that uses an electrical current to move substances through the skin or across other body surfaces such as the eye. Although the effect was first noted in the eighteenth century, its use in medicine only became popular after 1900, following the publication of a series of papers on the subject by the French physician Stéphane Leduc.
Iontophoresis works on ions – water-soluble substances that have a positive or negative charge – and is based on the general principle that like charges repel and unlike charges attract. By using a direct (galvanic) current, an ion can be ‘pushed’ into the skin if the electrode (the active or working electrode) being used has the same charge as the ion in question, i.e. a positive ion (cation) will be pushed into the skin by a positive electrode (anode) and a negative ion (anion) will be similarly affected by a negative electrode (cathode). In some cases therapists refer to each process separately – cataphoresis when the positive electrode is the working electrode (it pushes cations) and anaphoresis for when the negative electrode is used (it pushes anions) – but as this can be confusing both processes are often simply referred to as iontophoresis.
Working electrodes come in a variety of forms including balls, rollers, disks and full face masks. As a direct current is used, another electrode (the passive, indifferent or return electrode) is required to complete the electrical circuit and get the current to flow. This electrode can be a bar, given to the client to hold, or a pad placed somewhere where it makes good body contact, e.g., under the shoulder or wrapped around the upper arm.
Because it is very difficult to move water-soluble chemicals across the skin’s surface, when it was first introduced the medical profession hoped that iontophoresis would be a good method for delivering drugs. Unfortunately, due to a variety of factors – including the excellent barrier properties of the skin – this has not held up in practice and it currently has limited medical applications, such as treatments for hyperhidrosis (abnormal sweating of the palms or other areas of the body).
Electricity had been used to increase skin penetration before the arrival of iontophoresis in salons. The main aim of these electrical treatments was to redden the skin, which it was believed increased absorption by increasing the blood flow. So, even if some ions were moved in the process, it was not a true iontophoretic treatment.
After the paste has become thoroughly dry it may be removed by washing the skin with luke-warm water, and then if the patches on the face or neck are very deep, the bleaching lotion may be forced into the skin by means of the negative electrode, … continuing the process until the skin is thoroughly reddened. This process, it should be understood, is only used for moth patch or chloasma, and would not be used in the ordinary treatment at all.
Red light was believed to work in a similar fashion and was also employed in many early salons.
See also: Red Light, Blue Light
The earliest record I have for iontophoresis as a salon practice is by Helena Rubinstein in 1935, but it is likely that it was a treatment regime in French salons before this.
One compound used in these early iontophoretic treatments was sulphur. Used with the positive electrode, sulphur solutions were employed to treat acne-prone skin or seborrhoea. Iontophoretic solutions used in salons today are made with a wide variety of ingredients including vitamins, minerals, collagen, elastin, amino acids, hyaluronic acid and a range of animal and plant extracts. These come in a range of prepared packages including gels, serums and ampoules. Therapists are usually provided with very little information on how these work, other than the skin condition for which they apply and the polarity of the electrode to be used. As with many ingredients in skin creams, it is doubtful whether some of these substances could penetrate the skin, whether or not an electric current is used, let alone whether they would be effective.
Claims for iontophoretic treatments include hydration, repair and regeneration of mature or damaged skin, stimulation of sluggish circulation and, in the case of body treatments, the softening and absorption of fat and cellulite. Many of these claims are suspect, given that they rely on the transfer and action of specific ingredients deep into the skin.
Iontophoretic treatments which required the operator to reverse the polarity of the electrode – change from negative to positive or positive to negative – are particularly dubious as the opposing polarity would reverse any effect previously generated by the opposite electrode and ions that were hitherto ‘pushed’ into the skin would now be ‘pulled’ out of it.
Another galvanic treatment that appeared contemporaneously with the introduction of iontophoresis was ‘de-incrustation’. This treatment – developed by the Société P.A.B. in France – used a direct current to remove ‘incrustations’ from the skin.
The developers of the treatment described these ‘incrustations’ as ‘microscopic crystallisations’ formed by chemical reactions between certain chemicals and minerals in creams, make-up, atmospheric pollution and perspiration. As the impurities built up they clogged the skin causing wrinkles, pimples, acne and blackheads. They had to be removed, that is, the skin had to be ‘de-incrustated’.
The chief characteristics of the method consist in breaking up, reducing and eliminating all the impurities (waste matter, dust, toxins, crystallisations, etc.) which block up the glandular tubes. … The immediate result is—increased blood circulation and, gradually, recolouring of the epidermis.
Incrustations could be eliminated without electricity either by undertaking a deep-cleansing facial treatment – using cleansers, warm sprays and massage – in a salon or by using a facial scrub at home. In France these treatments were also known as désincrustation but in the English speaking world the term usually only applies to the electrical treatment.
Electrical desincrustation relies on a well-known effect of direct (galvanic) currents, that an alkali (sodium hydroxide) is produced at the negative electrode and an acid (hydrochloric acid) is generated at the positive electrode.
This chemical reaction was well known in the nineteenth century and was the basic science behind the electrical removal of unwanted hair through electrolysis.
See also: Electrolysis
Unlike electrolysis, where the sodium hydroxide (lye) is concentrated in a small area in the living dermis of the skin through the insertion of a needle, in desincrustation the sodium hydroxide is spread over the stratum corneum of the epidermis. So, rather than destroying tissue, as in electrolysis, in desincrustation the sodium hydroxide merely softens the keratin in the epidermis. This assists in desquamating surface keratinocytes and loosens any hard plugs of sebum such as those that occur in blackheads. The treatment is therefore commonly employed on ‘congested skin’ as precursor to extractions.
See also: Enlarged Pore and Blackhead Treatments
As with iontophoresis, the negative electrode used in desincrustation can be a disk, roller or ball electrode, a full facial mask, or something as simple as a tweezer electrode encased in a pad of cotton wool soaked in conducting solution. Unlike iontophoresis, where specialised ampoules are needed, a simple salt solution is all that is required. One can be made up using the following formula:
|Baking soda (sodium bicarbonate)||5 ml (1 teaspoon)|
|Distilled water||250 ml (1 cup)|
Sodium bicarbonate beaks down into sodium (positive) and bicarbonate (negative) ions when dissolved in water. This makes the solution slightly alkaline making it more effective than using common table salt (sodium chloride). In the 1930s, I believe a copper sulphate solution was also used but this would not be recommended today.
The recommended treatment in the 1930s started with a cleansing massage to soften and hydrate the skin as much as possible. A warm pulveriser or steam bath under coloured light may also have been used to improve the skin hydration.
See also: Vapourisers (Steamers & Atomisers)
The client was then connected to the positive pole while the operator worked on the face with the negative pole saturated in solution. The session generally lasted about 10 to 15 minutes depending on the strength of the current used and the sensitivity of the skin to electricity. Most subjects could conveniently withstand a current of between ½ to 3 milliamps with the strength of the current adjusted to suit the client.
In order to carry out either desincrustation or iontophoresis, a salon had to purchase a galvanic machine. Having done so it made sense for them to maximise the return on their outlay by combining iontophoresis and desincrustation into a single treatment. This was commonly done by first carrying out desincrustation, using the negative electrode, and then following this with iontophoresis, using the positive electrode.
The reasoning behind this is as follows. Using desincrustation first reduces the barrier properties of the skin by assisting with exfoliation, in theory making it easier for ions to move across the skin during iontophoresis. Then, as acid is produced under the positive electrode with iontophoresis this helps to restore the acid balance of the skin upset by the alkali generated during desincrustation.
Updated: 30th October 2016
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Guinot, R. (1937). La peau et la désincustation. La Parfumerie Moderne. November, Number 11, 417-223.
The hairdresser and beauty trade. (1934). London.
Kovacs, R. (1949). A manual of physical therapy (4th ed.). Philadelphia: Lea & Febiger.
Lloyd, E. (1907). The skin. Its care and treatment (3rd. ed.). Chicago: McIntosh Battery and Optical Company.
Simmons, J. V. (1989). Science and the beauty business. Volume 2. The beauty salon and its equipment. London: Macmillan.