Botox and dermal fillers – what, why how and who

Botox is a popular treatment for the prevention and reversal of fine lines and wrinkles, however, most people do not fully understand what Botox is, what Botox can be used for and whether Botox is the only treatment available for semi-permanent reversal of extrinsic caused ageing. Is Botox safe? Does Botox have side effects? What’s the difference between Botox and dermal fillers? In this Botox review, we delve into the science behind all of these questions.

What is Botox?

Botox is the brand name of an injectable toxin with the ability to freeze muscles i.e. stop muscles from contracting. Scientifically known as botulinum toxin and often abbreviated to BTX, the first instance of Botox being used for anti-ageing benefits was noted in the mid-1980s, however supporting scientific studies weren’t published until much later in 19921.

Interestingly botulinum toxin is thought to be the most potent poison in known existence. Scientists estimate just 1 gram could be all that’s needed to kill 1 million people2. Helpfully the doses used in Botox injections are infinitely smaller than this. Botulinum toxin is a species with 8 subtypes of botulinum toxin – each is alphabetically numbered from A to H. Type A is the species used in a Botox injection.

What is Botox made out of?

Even more interestingly Botox is a protein which is manufactured organically by a bacteria referred to as Clostridium botulinum – when found in food and if ingested the same toxin can be responsible for human botulism.

As Botox is a neurotoxin, the consideration of treatment should not be taken lightly. However, it should also be noted – dose makes the poison.

How does Botox work?

Fine lines and wrinkles may be formed as a consequence of intrinsic or extrinsic ageing factors. Intrinsic causes of ageing are largely determined by a person’s genetics i.e. they’re caused internally and therefore are not easily controlled or mediated. Extrinsic causes of ageing are caused by a person’s environment i.e. sun exposure or facial expressions and are therefore more easily controlled.

Botox injections aim to prevent and reverse extrinsic causes of ageing, specifically the formation of fine lines and wrinkles caused by the simple act of moving facial muscles. Dermatologists refer to these expression lines as dynamic wrinkles meaning they’re predominantly caused by movement.

Smiling, frowning, squinting, furrowing and focusing can all provoke movement of facial muscles and therefore the creasing of skin. When skin is youthful, healthy levels of collagen (a supportive skin protein) and hyaluronic acid (a skin plumping polymer which works by absorbing and retaining water) allow the skin to bounce back from expression caused creasing. As skin ages, collagen levels decline and existing collagen networks can become toughened and damaged. Hyaluronic acid levels are also changed with hyaluronic acid levels found in the epidermis (the top layers of skin) being significantly decreased and hyaluronic acid found in the dermis (deeper layers of skin) having a decreased ability to bind to tissues. Such age-related changes contribute to dehydration, atrophy, and loss of skin elasticity3.

What does Botox do?

Botox can help prevent and reverse wrinkles by preventing skin from creasing. When skin is not able to crease existing fine lines and wrinkles may re-plump (to a degree) with time and future fine lines and wrinkles caused by skin creasing may be prevented.

Botox does this by interfering with the signalling which causes a person’s facial muscles to contract. Nerve fibres connected to muscular tissue become activated by a neurotransmitter called acetylcholine. This process can be imagined as a cup, ready to receive a ball. In normal activation of facial expression acetylcholine – as the ball – is released and when received by the cup – muscle movement is activated. After a Botox injection, acetylcholine release becomes inhibited, this is because Botox cleaves a protein (known as SNAP-25) which is essential for neurotransmitter release. Without acetylcholine release, muscle contractions are prevented and therefore skin may be prevented from forming dynamic wrinkles4.

Best results from Botox: What age does Botox have the best effect?

Botox can both help prevent and reverse the formation of wrinkles, however as an anti-wrinkle treatment, Botox in undoubtedly better at prevention. A 2002 published, placebo-controlled trial concluded the benefits of Botox were not as great in patients older than 50 years5. This was proposed to be due to 2 key factors;

General loss of dermal elasticity with age i.e. collagen decline
Repeated muscle activity may cause subdermal fibrotic connections which could lead to permanent facial lines
The same study authors, therefore, concluded that early treatment with Botox could prevent the formation of permanent wrinkles later in life.

Is it safe to use Botox?

A recent large sale clinical trial decisively investigated the safety of Botox when used to treat frown lines6. The study was placebo-controlled meaning one group were injected with Botox and another group were injected with the same carrier solution but without Botox. Overall the study concluded a Botox treatment is safe and well tolerated with most frequently complained of side effects being caused also by the placebo i.e. they were not a consequence of the Botox active;

Headache – Botox group 15.3%, placebo – 15%
Respiratory tract infection – Botox group 4.9%, placebo – 8.3%
Blepharoptosis – Botox group 5.4%, placebo – 0%
Back pain – Botox group 1.5%, placebo – 5%
Acne – Botox group 1%, placebo – 5%
Headaches reported by trial patients occurred within 2 days of treatment and were mostly rated as mild lasting only for a few hours. As both patients receiving Botox and placebo had an equal incidence of headaches, this side effect is likely due to the injection itself and potentially the stress of undergoing a somewhat invasive procedure.

What are the bad side effects of Botox?

Blepharoptosis is the medical definition of what may colloquially be described as upper eyelid droop or sag i.e. where a person’s upper eyelid lies lower than it normally would when gazing straight ahead. During Botox treatment it’s thought an amount of active may in some cases be caused to diffuse down into the eyelid area, therefore, causing blepharoptosis. Rather than being solely a side effect to treatment, this is also thought to be a side effect of administration – and a reason why Botox treatments need to be administered by qualified and well-trained clinics.

Of the study in question showing the Botox treatment group had a 5.4% risk of blepharoptosis – 66% were graded as mild with an average duration of 20 days, the remaining 34% were considered moderate with an average duration of 40 days.

How long does Botox last after the first time?

Botox is a quick acting treatment with the first results being visible within 24 to 72 hours after injection7. The above study also noted that by day seven every efficacy variable had improved almost to peak effect – which was seen after 30 days post-treatment. The same study also showed this optimal response was visible from 30 to 60 days post-treatment with effects of Botox still clinically visible after 90 days or three months. In over a quarter of patients, results continue to be visible at day 120 i.e. after 4 months.

In general Botox treatments are suggested to last for 3 to 6 months8. However, it’s also been suggested that as the total number of treatments increases the duration of Botox benefits lengthens9, 10. For a first time Botox user this would mean results are likely to last toward the 3 to 4-month mark.

Be aware which kind of Botox

There are 2 main commercially available formulas of Botox, the first is the American formulation – known as Botox, and the second is an English formula known as Dysbot – a blending of the company’s name (disport) and –bot from Botox11.

When having a Botox treatment it’s important to understand which blend a clinic uses as it may be different to the blend a previous clinic has used. This can lead to either ineffective results – when Botox is switched to the same concentration blend of Dysbot or the reverse i.e. side effects when switched the opposite way.

Formulas of Dysbot are known to be 4 times less potent than Botox i.e. for the same effect as Botox, Dysbot needs to be injected at a 4 times concentration. I unit of Botox is roughly equivalent to 4 units of Dysbot12.

What is the difference between Botox and dermal fillers?

Both Botox and dermal fillers can help smooth the appearance of fine lines and wrinkles however their modes of action are greatly different. Botox works by preventing a person’s facial muscles from contracting whereas dermal fillers work by plumping skin.

The most common type of dermal fillers are based on an injection of hyaluronic acid. When placed into deeper layers of skin it allows the skin to become voluminous meaning fine lines and wrinkles can be smoothed away. Hyaluronic acid is naturally present inside of skin becoming compromised with age. Dermal fillers reintroduce a powerful booster of the very same ingredient to visibly improve the smoothness of skin.

Both Botox and dermal fillers act to reduce the appearance of fine lines and wrinkles, however, Botox is best at preventing fine lines and wrinkles whereas dermal fillers are best at reversing existing fine lines and wrinkles.

How long do dermal fillers last?

Although dermal fillers are a type of injectable implant, the materials most frequently used i.e. hyaluronic acid can be metabolised by the human body. This, therefore, means fillers are not permanent. The natural human metabolism of hyaluronic acid is rapid, averagely being less than 24 hours inside of the skin. However dermal fillers of hyaluronic acid increase this by adding minute quantities of crosslinks to form an ‘implant’ in situ13.

Early clinical studies of a hyaluronic acid-based dermal fillers report that after 12 weeks of treatment an average of 82% correction was still visible, after 26 weeks i.e. 6.5 months, 69% of the dermal re-volumisation remained14. Another study reports 78% of patients maintained a moderate to marked improvement in 8 months post treatment15.

Do fillers last longer than Botox?

While fillers are studied to last longer than Botox it must be noted both treatments work in differing ways. As such the combination use of Botox and fillers can heighten non-surgical results with published papers claiming they can have a synergistic effect. Facial regions which benefit most from combination treatment are areas which have transitioned from dynamic to static lines, furrows and depressions i.e. dynamic wrinkles which are now permanent whether facial muscles contract or are smooth. Common treatment areas, therefore, include forehead furrows and a downturned corner of the mouth16.

Is Botox or fillers better for frown lines?

Established frown lines in patients over 50 years of age are best treated with a combination of Botox and dermal fillers. Botox shows only a moderate change in established frown lines as in mature skin their dynamic nature transitions into what are described as static lines or wrinkles i.e. wrinkles which are present regardless of whether facial muscles are moving.

Frown lines which are mostly dynamic i.e. only appear during expression are best treated with Botox. In the majority, this will be patients below the age of 50 years.

When deciding between fillers, Botox or a combination treatment it’s important to remember fillers add back volume whereas Botox freezes expression muscles. Fillers can treat static wrinkles whereas Botox will mainly treat dynamic wrinkles.


Sources and references

  1. A multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of botulinum toxin type A in the treatment of glabellar lines. J. Alastair Carruthers, Nicholas J. Lowe, M. Alan Menter, John Gibson, Marian Nordquist, Julie Mordaunt, Patricia Walker, Nina Eadie, BOTOX Glabellar Lines I Study Group
    J Am Acad Dermatol. 2002 Jun; 46(6): 840–849.

  2. Dhaked RK, Singh MK, Singh P, Gupta P. Botulinum toxin: Bioweapon & magic drug. The Indian Journal of Medical Research. 2010;132(5):489-503.
  3. Papakonstantinou E, Roth M, Karakiulakis G. Hyaluronic acid: A key molecule in skin aging. Dermato-endocrinology. 2012;4(3):253-258. doi:10.4161/derm.21923.
  4. Pellizzari R, Rossetto O, Schiavo G, Montecucco C. Tetanus and botulinum neurotoxins: mechanism of action and therapeutic uses. Philosophical Transactions of the Royal Society B: Biological Sciences. 1999;354(1381):259-268.
  5. A multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of botulinum toxin type A in the treatment of glabellar lines. J. Alastair Carruthers, Nicholas J. Lowe, M. Alan Menter, John Gibson, Marian Nordquist, Julie Mordaunt, Patricia Walker, Nina Eadie, BOTOX Glabellar Lines I Study Group
    J Am Acad Dermatol. 2002 Jun; 46(6): 840–849.

  6. A multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of botulinum toxin type A in the treatment of glabellar lines. J. Alastair Carruthers, Nicholas J. Lowe, M. Alan Menter, John Gibson, Marian Nordquist, Julie Mordaunt, Patricia Walker, Nina Eadie, BOTOX Glabellar Lines I Study Group
    J Am Acad Dermatol. 2002 Jun; 46(6): 840–849.

  7. Carruthers A, Carruthers JDA. Botulinum toxin in the treatment of glabellar frown lines and other facial wrinkles. In: Jankovic J, Hallett M, editors. Therapy with botulinum toxin. New York: Marcel Dekker; 1994. p. 577-95.
  8. Jankovic J, Hallett M. Therapy with botulinum toxin. New York: Marcel Dekker; 1994.
  9. Carruthers JDA, Carruthers JA. Treatment of glabellar frown lines with C. botulinum-A exotoxin. J Dermatol Surg Oncol 1992; 18:17-21.
  10. Ahn MS, Catten M, Maas CS. Temporal brow lift using botulinum toxin A. Plast Reconstruct Surg 2000;105:1129-35.
  11. DYSBOT: a single-blind, randomized parallel study to determine whether any differences can be detected in the efficacy and tolerability of two formulations of botulinum toxin type A–Dysport and Botox–assuming a ratio of 4:1. C. Sampaio, J. J. Ferreira, F. Simões, M. J. Rosas, M. Magalhães, A. P. Correia, A. Bastos-Lima, R. Martins, A. Castro-Caldas Mov Disord. 1997 Nov; 12(6): 1013–1018. doi: 10.1002/mds.870120627
  12. DYSBOT: a single-blind, randomized parallel study to determine whether any differences can be detected in the efficacy and tolerability of two formulations of botulinum toxin type A–Dysport and Botox–assuming a ratio of 4:1. C. Sampaio, J. J. Ferreira, F. Simões, M. J. Rosas, M. Magalhães, A. P. Correia, A. Bastos-Lima, R. Martins, A. Castro-Caldas Mov Disord. 1997 Nov; 12(6): 1013–1018. doi: 10.1002/mds.870120627
  13. Hyaluronic acid and its use as a “rejuvenation” agent in cosmetic dermatology. Pierre Andre Semin Cutan Med Surg. 2004 Dec; 23(4): 218–222. doi: 10.1016/j.sder.2004.09.002
  14. Injectable hyaluronic acid gel for soft tissue augmentation. A clinical and histological study. F. Duranti, G. Salti, B. Bovani, M. Calandra, M. L. Rosati Dermatol Surg. 1998 Dec; 24(12): 1317–1325.
  15. The first clinical study using a new biodegradable implant for the treatment of lips, wrinkles, and folds.
    Olenius Aesthetic Plast Surg. 1998 Mar-Apr; 22(2): 97–101.

  16. Hyaluronic acid fillers and botulinum toxin type a: rationale for their individual and combined use for injectable facial rejuvenation. Klein AW, Fagien S. Plast Reconstr Surg. 2007 Nov;120(6 Suppl):81S-88S.