One may apply oil to the hands or body on Shabbat in the manner that people normally anoint themselves for pleasure. Similarly, a woman may rub her hair or body with perfumed oil. It is true that the Sages forbade perfuming a garment, because scenting clothing involves Molid (producing something new that did not previously exist), which is similar to performing a melakha (Beitza 23a; Beit Yosef and Rema 511:4). However, there is no prohibition on applying perfume to the body or hair, because the scent is completely secondary to the body, and therefore it is not considered producing something new.
Although one may rub his body with oil, he may not apply cream because of the prohibition of Memare’aĥ, which is a tolada of Memaĥek (see below 18:6). Memaĥek refers to smoothing rough surfaces such as leather or wood, while Memare’aĥ involves evenly applying a substance to an object in order to make it smooth.
Therefore, one may not apply any type of cream or ointment to the skin, because in doing so one smoothes the cream onto the skin. Some object that this should not be prohibited, since the cream is meant to be absorbed by the body rather than to remain on the surface of the skin. However, this is incorrect, since even when one wants the cream to be absorbed, he also wants some of it to remain on the skin’s surface to make it smooth. Hence the prohibition of Memare’aĥ applies. In contrast, if the cream is watery, such that if it is left on a surface it will spread out, there is no prohibition of Memare’aĥ, and one may apply it to the body.
Liquid insect repellent may be used on Shabbat, but if it is a solid, one may not spread it on the body because of the prohibition of Memare’aĥ.
One who is experiencing mild discomfort may not apply medicinal oil. Furthermore, a healthy person may not apply medicinal oil for pleasure, since the Sages prohibited the use of medicines on Shabbat. However, if one is truly suffering, he may use medicinal oil. If this oil is also used by healthy people, then since it will not be apparent that it is being used medicinally, even one who is experiencing discomfort may apply it (SA 327:1; below 28:4-5). The laws pertaining to massage, both professional and amateur, will be explained below (28:13).
. Some forbid making the body smell good, on account of Molid (Taz 511:8; MA 511:11; Ben Ish Ĥai, Year 2, Tetzaveh 11). At the opposite extreme, some maintain that one may infuse a garment with scent (Rishon Le-Tziyon, based on Rif, Rambam, and Rosh). However, most poskim maintain that while one may not make clothing smell good, one may make the body smell good (MB 128:23; Yeĥaveh Da’at 1:31; SSK 14:36).. If one would like all the cream to be absorbed into the body and none to remain on the skin, then there is no prohibition of Memare’aĥ (MA 316:24; MB ad loc. 49). Therefore, if one is sick enough that he may receive medical treatment on Shabbat, and he requires a cream, it may be spread on the skin and rubbed in until it is absorbed entirely by the body (Da’at Torah 328:26; R. Shlomo Zalman Auerbach cited in SSK ch. 33 n. 64). However, those who use cosmetic cream for pleasure or beauty do not want it to be entirely absorbed. Rather, they want some to stay on the surface of the skin, making it smooth and beautiful. Therefore, it is prohibited by Torah law to apply that cream.